Why Do Dogs Curl Up

Dogs like to lie down and rest in a variety of different positions. Many will nap on their sides or fall asleep on their stomachs. Some lay splayed out and appear relaxed, much like humans when we lie down and stretch into a comfortable position. When it comes to turning in for the night, your dog may prefer to curl into a ball in its bed. If you’ve ever watched a dog’s bedtime routine, you’ve probably noticed that dogs have a tendency to arrange their bed a certain way, as well. Here are some reasons that dogs seem to prefer this sleeping position, and what it can tell you about your dog’s personality.

When the ancestors of our domestic dog friends were living in the wild and survival was a priority, they would take refuge for the night in dug out dens or nests. In these environments, dogs had to learn to stave off the cold, protect themselves from potential threats, and still find a way to be comfortable enough to get a good night’s sleep. From these necessities, the curled-up position was born. The position keeps dogs warm, protects them from immediate threats, and is comfortable enough for them to get some shut eye. The instinct to sleep curled up persists in dogs today, especially in dogs that sleep outside, and has continued to be utilized by coyotes and wolves that live in the wild. As with other instinctive traits in modern, domesticated dogs, sleeping in a curled-up position means something a little different than it did in the original context. In the modern-day context of a dog’s life, especially for dogs that have the luxury of sleeping inside, the curled-up position tends to be used for either warmth, or a feeling of security. As many people correctly suspect, the position is not the most comfortable position to rest in. Dogs that sleep inside but feel unsafe, either as a result of stressors in the night or a change in environment, will adopt the curled-up position and feel comforted simply by being in the position. Their paws are tucked under their body, their tail is covering their face, and their muscles are tensed for any threat that could present itself while they sleep. Once a dog is completely comfortable in its indoor environment, it may adopt alternate sleeping positions. These include positions on the back and sides, which expose the belly and show that a dog feels completely comfortable in its environment. A dog that exposes its stomach would never do so if it felt even remotely threatened. This is why dogs that sleep outside, regardless of how comfortable they feel within their territory, will never sleep on their sides or on their backs. The curled-up position makes them feel safe, draws upon their instincts, and allows them to get the rest that they need to properly function. 

Most dogs are good about getting the sleep that they need to properly function, or they will sneak in naps here and there in lieu of a long night’s sleep. If your dog isn’t getting proper sleep, you will notice it in the frequency of naps and general lack of alertness that your dog displays. In this sense, being sleep-deprived looks a lot in dogs like it does in humans. The curled-up position does not afford dogs a lot of deep sleep, but some dogs do prefer it over other, more conventionally comfortable positions. The key to understanding your dog’s sleeping habits is to look for cues that your dog is getting deep, restful sleep. When a dog barks, twitches, or wags its tail in its sleep, it is giving a good indicator that it is getting deep sleep. The curled-up position can lead to deep sleep, but it is more commonly a form of light sleeping that allows a dog to spring up and react to any external stimulation. Dogs do not fully rest or get into deep sleep this way. If your dog sleeps inside and rests this way, it may be a sign that your dog is uncomfortable or stressed out by its environment. Look for ways to make your dog more comfortable and see if your dog’s sleeping habits adjust accordingly.

If your dog is napping frequently or curling up into a ball at random times during the day, the issue may not be related to sleep. Dogs that appear to be napping throughout the day may also be napping as a sign of severe boredom. In these cases, you might try playing with your dog more, or engage with your dog and be more mentally stimulating with it throughout the day. Dogs that curl up while awake might be doing so because they are extremely stressed or anxious. They want to feel safe and secure. In this case, try identifying the stressor and making your dog feel safer and more relaxed at home. A comfortable dog will sleep on its side or back; these are the most comfortable positions that provide the most rest.

In the same way that different humans prefer different sleeping positions, dogs will ultimately rest according to their preferences. There is nothing wrong with the curled-up position, and the level of security and comfort that it affords dog may be enough to give your dog a deep, restful sleep. Since it is the most prevalent sleeping position for dogs, it is enough to trust that your dog is getting the rest that it needs, so get some good rest yourself, and let sleeping dogs lie.