18 min read

How to Care for Hamsters, Gerbils, and Other Small Mammals


By Jasmine Sawatzky

Published: 03/24/2023, edited: 03/27/2023

Reviewed by a licensed veterinary professional: Dr. Linda Simon, MVB MRCVS

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Many people think of small mammals like hamsters, gerbils, guinea pigs, mice, and rats as starter pets. Sometimes they’re even bought for classrooms. But just because they’re little doesn’t mean they need less care. With some research and preparation, a small mammal could be a great addition to your family. Whether young or just young at heart, holding a little animal in your hands and looking into their mischievous eyes often brings a sense of wonder and joy.

Small mammal pets come in all different shapes and sizes with different personalities to boot. Some species are nocturnal, some burrow, some climb. Some are more social or more trainable than others. Each species has its own unique needs. 

We’ve compiled the most important tips for giving your furry little pal the happy habitat they deserve. Read on to find out how to set up your small mammal's home, how to bond and play safely, what kinds of food to feed them, and more. 

woman bonding with pet rat - How to Care for Hamsters, Gerbils, and Other Small Mammals

Bonding and socialization

One of the first things you may need to consider before picking up your new pal from the pet store is their social needs. Should you get one or two? How affectionate is the species by nature? Likely, you'll want to be able to bond with them to some degree, so they don’t become just a tiny roommate living rent-free in your home. Different mammals, however, have different needs when it comes to bonding with humans and socializing within their species. 

Bonding with your pet

Since they are prey in the wild, some small mammal species are naturally more skittish and distrustful and may take a little longer to bond with. This is especially true of hamsters. Gerbils and mice are also particularly skittish and quick. If these guys are handled from a young age, they usually have an agreeable temperament. Keep in mind hamsters are nocturnal and can be grumpy if woken during the day. 

Guinea pigs and fancy rats lean more to the affectionate side. They often enjoy human companionship and rarely bite, even when stressed. It’s pretty common for a rat to enjoy hanging out in your sleeve or shirt pocket. Mice and gerbils can still be pretty social creatures too despite being skittish. 

No matter the species, don’t give up, it is possible to form a close bond with your small mammal. Try to keep interactions consistent, even just a few minutes every day. Inconsistency can lead to confusion, which can lead to a lack of trust. By picking them up every day, they can become accustomed to being handled, which makes things easier for you! 

To get the bonding process started, try using some small treats like fruits or vegetables. Fortunately, small mammals are highly food motivated, so this will allow you to interact with them in a meaningful way. You can also try setting up an enclosure that’s attached to their home and sitting inside it. This will allow the little guy to come and go as they please while they get used to your scent and presence. Once some progress has been made, try teaching them some simple tricks like walking in a circle, stepping up onto your hand, or standing up on their hind legs.  

The main thing to remember when interacting with any pet is to keep it consistent and pawsitive! Soon they’ll be scurrying right into your hand. 

two white and black pet rats peering out of cage door


Some small mammals should be housed alone and can be prone to fight when housed together. Others are social creatures that live together in the wild and need the companionship of another member of their species to thrive. 

Guinea pigs are the most social of the bunch. In fact, in Switzerland, it’s illegal to own just one guinea pig. They need a roommate or they may suffer psychological damage and can even die of loneliness. The grief of losing their life-long buddy can cause them to become too depressed to eat. 

A group of rats is called a “mischief”, and that seems like a good enough reason on its own to keep more than one! Rats, mice, and gerbils do everything in groups when they live in the wild. This includes foraging, raising babies, grooming, and sleeping in a heap. They can live alone as long as you are able to spend a few hours a day playing with them, but they may not thrive as well. Be sure to keep the same sex together, otherwise you’ll quickly have more rodents than you bargained for! These guys are also territorial, so two or more crowded together without adequate space may fight.

Hamsters, especially the common Syrian hamster (or teddy bear hamster) needs to be housed alone. They may even fight to the death if paired with others, even their own siblings. The only exception would be the less common dwarf hamsters, which can live with or without same-species companions. 

If you follow these guidelines, you can have peace of mind knowing your little pocket pal is content while you’re away at work or school. 

two guinea pigs


Like any animal, your small pet could develop a health issue. Unfortunately, small mammals are extremely good at hiding when they’re unwell and continuing about their routine. The best way to watch your little pets' health is simply by spending enough time with them to know when something’s up. 

A healthy pet should have a normal, smooth gait, bright, clear eyes, healthy skin, and a soft, shiny coat that's free of dry patches, parasites, cuts, and swellings. Their bottom will be clear of any discharge, blood, or wetness. Every time you clean the cage, it’s good practice to run your fingers gently over their body to check for lumps and bumps and ensure that they are not too skinny or fat. 

Some signs of illness to look for include:

  • Weight loss
  • Eating less than normal 
  • Only eating soft foods
  • Drooling
  • Diarrhea
  • Less active than normal, lethargic
  • Unkempt coat, not grooming
  • Lumps or bumps anywhere on the body
  • Hair loss
  • Scratching all the time
  • Coughing or rapid breathing
  • Sores or red skin on their feet
  • Increased sneezing and mucous from the nose
  • Increased snuffling sounds in the nose and upper respiratory tract
  • In rats and mice, increased porphyrin (red staining around the eyes and nose)

pet mouse hiding in tunnel enclosure

Types of illnesses and diseases that can affect your small pet can vary by species, age and genetics, but there are some commons issues to be on the lookout for. 

Respiratory infections

Respiratory infections are relatively common among rodents. You can help prevent them by keeping your pet's cage clean and well ventilated. Dusty cage litter, aromatic cedar chip bedding, and high levels of ammonia from urine accumulation in dirty litter or a dirty cage could irritate the respiratory tract and predispose a pet rodent to a respiratory infection. It’s also possible for certain types of bedding such as cedar to cause allergies or irritate the skin. Try to keep your pet's cage as clean and comfy as possible to help them stay healthy. 

Dental health

Your small mammal's chompers are something to keep an eye on as well. A rodent's teeth grow continuously throughout their whole life. Occasionally, these teeth grow too long and cut into the gums, causing pain, and interfering with eating and grooming. Rats and mice can have problems with their front incisors, while guinea pigs will have issues with their molars. It’s important to provide plenty of things for your pet to chew on to help wear down their teeth. 

Gastrointestinal issues

Wet tail is a common gastrointestinal disease among rodents that can be caused by bacterial infections, stress, and dietary issues. Longhaired teddy bear hamsters are especially prone to the disease. Small mammals with diarrhea can quickly become dehydrated, so it’s important to bring them to the vet if the issue doesn’t resolve soon.


Diabetes is another common problem in hamsters, which will show itself with excessive thirst and urination. Try to make sure your hamster doesn’t get too overweight to help prevent diabetes. 


Sadly, rats are genetically predisposed to developing cancer and tumors. Some are malignant and some are benign. They can sometimes be seen or felt externally. If you feel a lump, bring your little buddy to the vet to have the tumor examined and possibly removed. 

If you’re familiar with your pet's normal appearance and behavior, it shouldn’t be too hard to tell when they need some help. Got more questions about your pocket pet’s health? Chat with a veterinary professional today for advice to keep them in tip-top shape. 

gerbil playing with wicker balls


Our furry little friends have different sets of instincts and behaviors. Each species seems to have their own cute idiosyncrasies! Learning about each one will help you pick your favorite. 

Gerbil behavior

Gerbils are playful little creatures that love being in groups. They will play by chasing each other around, wrestling, and boxing. One behavior that’s unique to gerbils is thumping. This is when they pound both hind legs into the ground when they are excited or stressed as a warning to other gerbils, or as a mating ritual. Often, if one gerbil is startled and begins thumping, others in the enclosure or room will also begin thumping. It can be surprisingly loud considering their petite size! 

Hamster behavior

Hamsters are nocturnal, so it’s common to see them dozing during the day and getting up to their antics at night. They can be highly energetic and will even exercise for three to four hours each night. They instinctively burrow or hide as a means of protection and staying safe. This is why you’ll often see tunnels connected to hamster cages. They chew on wood and crunchy treats to grind their teeth down. Much like a squirrel, they fill their cheeks full of snacks and bury them in special hiding places. They can also use their cheek pouches to carry bedding material and transport their babies. Hamsters can carry up to 50% of their body weight in their cheeks! If you observe some relaxed grooming, burrowing, and lively acrobatics, all is well in the hamster house!

Guinea pig behavior

Guinea pigs have funny little quirks that make them special. They’re known for something called popcorning, a little move that looks like this: run, jump in the air, land on all fours, bounce up in the air again and turn the other way. A popcorning guinea pig is a happy piggy! Because they’re prey animals, they can be startled easily and either dash or freeze. Guinea pigs can be pretty vocal, and really live up to the “pig” name by squealing and squeaking. They chatter when they’re angry, and a relaxed guinea pig might make a soft but consistent squeaking/whistling sound, which is often accompanied by little body vibrations. You may also see your little piggy standing on two legs to get a better view and raising their heads to show dominance.

Rat behavior

Many people cringe when they think of a pet rat, but it’s possible they have all the other small pets beat for being clean, friendly, and intelligent. They love a bit of problem-solving and bond easily with humans. They’re pretty similar to other small mammals in their burrowing, gnawing, and night-time antics. They love being in groups and seem to enjoy the occasional tussle with a cagemate: chasing, pinning, and some vocalizations are normal. Rats love climbing, and you can encourage this exercise by providing rat-safe ropes, ladders, and climbing toys. Don’t be surprised if you see them climbing your drapes!

Mice behavior

Mice play like children in a playground. You’ll also see them grooming, burrowing, and grinding their teeth frequently. Since mice don’t have great eyesight, they’ll wiggle their whiskers to help them navigate. A mouse's body language will tell you a lot! If they’re annoyed, they will wag their tails and point their ears down and back. If they’re happy and having fun, their tiny ears will be pointing upward. 

pet gerbil walking on human hands

Common behavioral problems in small mammals

If your small mammal isn’t having their mental needs met, they may start exhibiting some behavioral problems. This commonly looks like: 

  • Biting
  • Bar chewing
  • Cage possession
  • Changes in appetite
  • Excessive digging
  • Overgrooming
  • Inter-animal aggression
  • Pica

These problems can occur if your pet isn’t experiencing enough enrichment or stimulation. Take a moment to step back and evaluate the normal environmental and social needs your particular species would have in nature. Could the problem be their companions or lack thereof? Do they have opportunities for exercise? Do they have enough toys and chewing options? Do they have enough space and available hiding places? What about supervised time outside of their cage? Any of these issues could lead to boredom and frustration in your small mammal. 

Not every fight needs intervention, but if it starts getting serious or any blood is drawn, your pets need to be separated. It could be that they’re trying to establish dominance, they’re in pain, the cage is too small, or they’re bored/unhappy. Try to check if your pets are physically ok, and make sure they have enough space and stimulation. If all their physical and mental needs are being met, your critter cage should be a peaceful habitat. 

hamster in cage with tunnel and wheel

Enrichment and exercise

We’ve just discussed some of the major behavioral problems that can begin to happen if your little pet isn’t getting enough enrichment and exercise. They ​​are busy, active, intelligent creatures who require daily enrichment so that they can be physically and mentally healthy. So how much enrichment and exercise do they need, and how can you provide it? 

Providing enrichment for your pal can be fun and easy. You can even use things you find around the house! Cardboard boxes, toilet paper tubes, paper towel tubes, cardboard egg cartons, and paper bags (never plastic) are loads of fun for little critters. Be sure to remove any tape or labels first. Try hiding some treats in them or build a maze for your critter to traverse! Your local pet store should also have plenty of options you can buy, like puzzles, and hard plastic or wooden toys. 

A running wheel or spinning disk is a must in gerbil, mouse, rat, and hamster cages to encourage exercise. Try to find one with a solid enclosed tread and side so that no toes or tails get caught. There are plenty of wheels on the market that are virtually silent! Rats love to climb, so some climbing platforms, ropes, and ladders will provide a way to blow off some steam. 

Wheels don’t work great for guinea pigs, as they need a little more space than an in-cage exercise product can provide. Instead, these animals can benefit greatly from a little time out of their cage every day. If they aren't allowed to roam free, they may become overweight or overly shy and sullen. In fact, all small animals need to spend some time out of their cages for exercise. The extra space could be a great chance to try setting up an agility course! 

When letting your pet out of their cage indoors, be sure the area is free from dangers. This could include any wires, cables, poisonous plants, or other pets. There’s a possibility of them chewing anything they find. You can purchase pens or even harnesses for your small pet, just be sure you buy the one appropriate for your species as they can be great escape artists! 

If you decide to let your pal outside, make sure it’s at a comfortable temperature and out of direct sunlight. Avoid grass that’s damp or has been treated with pesticides. An area with a cover overhead is best to protect them from predators like hawks. Since rodents are prey animals, they may become quickly overwhelmed. Be sure to provide places to hide like boxes or PVC pipes. Ease them into it slowly and remember, it’s supposed to be fun! 

two pet mice on a table and in a bowl


Training your small pet to do some basic tricks is a great way to bond, offers some mental stimulation, and is fun for everyone. Rats are by far the easiest and most responsive small pets to train. These social creatures quickly learn to trust people. Gerbils are probably next on the list because they’re curious and interested in humans. Hamsters can be the most difficult to get to know, but with a bag full of treats, any pet can be won over! 

Before jumping into training your pet, let them adjust to your home. Moving can be stressful for them. Remember that most pets are nocturnal, so try to train them in the evenings or when they’re the most active. It should be in a quiet and calm setting so your pet doesn’t get startled. The point is for it to be a fun, bonding experience, so be patient. Animals can pick up when you’re frustrated. 

There are some basic commands that all pets can learn, and some of them are very practical! Teaching your pal to come when called, use a litter box, or not to bite are very useful tricks. It would be great if your guinea pig has these commands down pat when they go for their daily wander! Most pets can also be taught simple things like standing up on two legs, spinning in a circle, or shaking a paw. 

After grasping some of the more basic commands, rats and gerbils can be taught more advanced tricks and even agility. They can learn to tightrope walk, sit on your shoulder, jump through hoops, and even fetch. After your rat shows off their tricks to your friends, it won’t be hard to convince them rats are actually extremely intelligent and fun pets. 

guinea pigs eating a carrot next to food bowl with pellets


Hamsters, mice, rats, and gerbils are omnivores and require the same diet. It should consist of a commercial pellet mix, seeds, and fresh produce. You should also offer small bites of other foods each week. This not only provides a diet more similar to what they would eat in the wild, but it can stave off boredom too. Be sure to give them treats as part of their daily food allowance, not in addition to it, or it could cause obesity or health problems. Some treats could include fresh fruits and veggies, whole grain bread and cereals, or hard-boiled eggs. Stay away from sugars and high-fat foods such as dairy. 

Guinea pigs, unlike the other mammals in this group, are herbivores. They need a balanced diet of pellets, hay, and fresh vegetables. Just like humans, guinea pigs can’t make their own vitamin C, so they require vitamin C-rich foods in their daily diet. Along with their 1/8 cup of pellets once a day, they need an unlimited supply of timothy hay. This helps aid their digestion and limit the growth of their teeth. A small wedge of orange or apple, several blueberries, or a thin slice of banana is a perfect snack. Kiwis, strawberries, and citrus fruits have high levels of vitamin C, just be sure to keep the portion sizes small because of their high-sugar content. Since guinea pigs are herbivores, don’t try feeding them things like eggs or dairy. 

While there are many fruits and veggies we eat that can be shared with our critters, some are toxic to most small mammals and should never be given to small mammals, including: 

  • Onion
  • Garlic
  • Avocado
  • Apple seeds
  • Citrus fruits for mice, gerbils, and hamsters
  • Grapes for rats, mice and gerbils
  • Walnuts
  • Rhubarb
  • Raisins
  • Chocolate

Interestingly, some of the exceptions to that list are that hamsters and guinea pigs can eat grapes, and guinea pigs and rats can eat citrus fruit. If your pet gets into any of these foods, it could lead to sickness and even death. It’s a good idea to call your vet if you saw them eat anything toxic. Always provide your pal plenty of fresh water and remove any uneaten food the next day so it doesn’t mold. 

hamster in blue cage


Once you’ve decided exactly what little pet you want to buy, it’s time to start setting up their home! It’s quite clear by this point that every species has their own unique needs. Here are some things to consider. 

Types of small mammal cages and enclosures

When you walk into a pet store, you’ll see a big variety of cages and enclosures that come in wire, glass, or wood, and in all shapes and sizes. Here are some principles you can follow, but remember the sizes are minimums. When it comes to cages, the bigger the better! 

For rats, a wire cage is best - the larger and taller, the better, because rats are active and love to climb. The minimum suggested cage size for two rats is 28 inches long x 14 inches wide x 17 inches high, but try to factor in more space for toys and structures. 

Hamsters love to dig and climb, so cages with deep plastic bases and wire tops work well. Aim for a minimum of 24 inches long x 12 inches wide x 12 inches high. You can often find fun cages with built-in tunnel systems your hamster will love. 

Gerbils and mice are often housed in aquariums so they can’t escape. Make sure the tank has ventilation holes in it (as some vivariums do) and a secure wire lid. Try to provide things for the mice to climb, and plenty of bedding for gerbils to dig through. Wire cages also make great homes, as long as the spacing is no greater than ¼ inch so they can’t wriggle out. You’ll want to aim for 10 gallons of space per gerbil. The rule of thumb for mice is 18 inches long x 12 inches wide x 12 inches high. For each additional mouse, increase the floor area by half a square foot.

Guinea pigs prefer flat, open spaces, and are even sometimes afraid of heights, so no need for a multi-level cage. Two guinea pigs need a minimum of a 10 1/2 square foot cage, while three guinea pigs need a minimum of 13 square feet, and four guinea pigs need a minimum of 16 square feet.

gerbil in cage with wood shavings for bedding


Now that you have the perfect cage, it’s time to decide what sort of bedding to put at the bottom. Bedding is important because it provides comfort and support while your pet is sleeping or resting. It helps absorb moisture that comes from waste, eliminates odors, keeps them warm and provides privacy and shelter. Some common options are wood shavings, shredded paper, straw, cloth, corncob, and hemp shavings. The good news is that all of these are compostable, except for the cloth. The best one will absorb urine well and keep your pet dry and healthy and doesn’t contain any harsh chemicals. Let’s find the goldilocks bedding for your fur-baby. 

Paper-based bedding is arguably the most popular and commonly used bedding. It’s soft, comfortable, and comes in a variety of colors. Because it’s light and delicate, it can make burrowing a challenge for some pets. Be sure to avoid printed and scented paper beddings because they can contain harmful toxins that will harm your animal's health. 

If you decide to go with wood shavings, aspen and kiln-dried pine are the only viable options. Untreated cedar and pine may smell great, but they give off poisonous fumes that can make your pet sick. They’re also hard and can form sharp splinters. Aspen shavings are affordable and absorbent, but they may stick to the fur of pets with longer fur like hamsters, and produce some harmful dust. If you want to go the organic route, try hemp shavings. Hemp is a great hypoallergenic choice for people and pets who suffer from respiratory problems. It’s also highly absorbent, soft, great for tunneling, and generally affordable. 

Straw and corn cob bedding are mostly a thing of the past because they can have problems with mold and don’t absorb moisture very well. 

Cloth bedding is a viable option for animals that are allergic to other types of bedding. It produces no dust, looks nice, and may be comfy. Keep in mind you need to be willing to clean it every day because it keeps the feces on the surface. Make sure it’s not tattered so it doesn’t entangle your animal's feet. 

two pet rats in a cage

Cleaning your pet’s enclosure and litter box

How often you need to clean your pet's enclosure will depend on the type of bedding you choose, how many pets are using the space, and whether they use a litter box. A dirty cage can lead to a slew of health problems, like respiratory and gastrointestinal issues. 

Every day when you feed or handle your pet, check on the status of the cage and do some spot cleaning. Clean out the food and water bowls before refilling them, and remove any uneaten produce before it gets moldy. Remove any soiled litter or bedding. This will go a long way in preventing stains and odors from becoming a problem. It can also help you keep an eye on your pet's eating and bathroom habits and watch for any concerns. If your pet's bathroom habits change suddenly, it may indicate that they’re ill and they need to visit a vet. 

Every week, you’ll want to do a deeper cleaning on top of the daily tasks. After placing your pet in a backup cage or pen, dispose of the bedding and use hot water and soap to give the cage, aquarium, or habitat a more thorough cleaning. Wash any fabric bedding, and give any toys and perches a cleaning. Make sure the cage and any fabric bedding have completely dried before returning your pet to their home-inside-your-home. 

guinea pig being held in human hands


Have you ever seen something so cute you want to squish it? There’s a term that’s been coined for that, it’s called “cute aggression”. Although the average person feels this out of love and would never actually want to harm their animal, how much cuddling is too much? How can you handle your pet safely?

Hamsters, rats, mice, gerbils, and guinea pigs are all very delicate creatures. Even though guinea pigs are bigger, they still have thin bones and need to be handled gently and confidently. In the wild, the only time rodents are lifted off the ground is when they’re in the grip of a predator, so it’s important to build some trust with your small pet first. Building trust may take a little longer with hamsters. Try taming them from a young age and handling them regularly. 

Start by allowing your pet to get used to your presence. Hold some treats and allow them to stand on your hand, gently cupping them and letting them leave as they please. Gerbils and mice are speedy, so it may take a little longer with them. When they’re ready, pick them up slowly by grasping them around the shoulders, just behind the front legs, and use your other hand to support their bottom. Hold them close to your body, so they feel safe and secure.

Small mammals can move quickly and may try to jump from your hands, so hold them while you are sitting to prevent them from falling and getting hurt. Never grab a rat, gerbil, or mouse by its tail as this can cause serious injury, as well as being painful. Be sure to teach children how to handle them correctly and watch them so the animal doesn’t get dropped or squished. 

While you’re holding your little buddy, keep it enjoyable by giving them treats and petting them. It’s a good time to check the condition of their fur and skin. Soon they’ll be falling asleep in your palm! 

gerbil sitting in a black bowl

Your experience with small pets is sure to go furtastically if you follow the tips in this guide! 

Here’s a quick recap of the points we covered above:

  • Some species are more social than others. Be patient bonding with them, and pair them with a buddy if they need it. 
  • By handling and watching your pet regularly, you'll be able to tell if they're unwell and need a visit to the vet. 
  • Each species has their own personality and quirks! But if they start showing frustration or aggression, you may need to do some troubleshooting. 
  • Providing enrichment and exercise is not only essential for your pet's well-being, but it's fun too! 
  • Different species can learn different degrees of tricks. Be sure to use plenty of low-calorie treats! 
  • Try to imitate the diet your pet would have in the wild by including fruits and veggies. 
  • Your pet will love their home if it's dry, clean, comfy, and large enough. 
  • Remember rodents are delicate and skittish, so handle with care! 

Book a drop-in to care for your small mammal when you are away by downloading the Wag! app, your one-stop source for all your small pet's care needs. 

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