Dogs have very keen senses. They are able to take in and neutrally observe a wide variety of aspects and interpret the emotions they are feeling. We have all likely heard of dogs, who are normally friendly and loving, acting strangely like barking, growling, or hiding behind their owner's legs in the presence of someone new.  

Such behavior leads us to believe that dog sensed something bad, or off, about the person whom which they acted negatively to. Is there any truth in the theory that dogs can indeed sense "bad" people? Turns out, there is quite a bit of research and truth in these sentiments!

If you ever find yourself in a situation where your dog does not like someone or acts differently with a person than they normally do, you can very easily tell they have reservations about that person. If your dog is generally very happy, excited, and trusting around new people, they will likely do things like jump up in excitement at the new person, rub their body against the person's legs, wag their tails quickly, perk their ears up, lick them, and some dogs will even bark or make silly noises when they like the person who is giving them attention. 

On the other hand, if your dog doesn't like the person, their reaction to them will be significantly different. Your dog may show signs they are fearful by cowering away from the person, hiding behind your legs, dropping their tail between their legs, dropping their ears, or they may even try and walk or run away from the person. 

Depending on your dog, they may also show some signs of aggression as well. Your dog may bark angerly, growl, show their teeth, lunge at the person, or even snap! If you have a dog that is a protector, they may also try and guard you against the "bad" person they are sensing or pace around you with agitation. 

Dogs have always been intuitive creatures and are able to tap into their senses and trust their gut feelings. Humans experience gut feelings about people, as well, so, it could be said that dogs experience this in a similar way. 

However, it is believed by some that dogs can sense negative people and energies on an even more intense level. This is because dogs are able to trust their gut-feelings and emotions without overthinking or trying to deny them, where humans generally go through that process. These feelings and emotions are often described as a sixth sense. A sixth sense is the ability to infer what the true nature of a situation or a person really is. This is why many dogs react to negative and bad people so quickly.

For centuries, dogs and many other animals have survived based on their instincts. In the wild, dogs would have to react quickly to certain situations, many times negative, in aggressive and assertive ways in order to protect themselves from danger. Domesticated dogs have kept this trait as they evolved and still heavily rely on these special instincts to protect themselves and their owners. 

It is very common to hear stories from dog owners about their dog sensing someone with negative energy or bad intentions. For example, dogs who are generally very friendly, never bark at people, or are always happy to great new people will cower away or act in an aggressive manner when meeting a new person they deem as "bad."

Believe it or not, there is a very simple and easy scientific explanation as to why your pup can sense a bad person or a person with bad intentions. When a person has bad intentions, act in a bad or negative way, or have evil feelings or thoughts, the human brain transmits and releases certain chemicals. 

For instance, if someone is about to do something bad, adrenaline increases and, in turn, makes the person sweat much more than normal. Since dogs have a very keen sense of smell, they are able to pick up on these scents and changes within a few seconds and react to them. The dog's instincts kick into gear and they become more alert and aware of what is around them. If they are sensing something out of the ordinary, either fear or protection/aggression will manifest in their actions and demeanor. 

As you may have guessed, there is no way to train your dog to sense bad people. This is because these reactions happen on an instinctual, biological level. It is not necessarily a learned behavior. However, what you can do is help "train" your dog to react in a safe and non-aggressive way around people they sense as "bad." 

Like we talked about previously, many dogs will show dominance or aggression when they experience a negative person with bad energy. They are likely doing this in order to protect you, but it is important to make sure your dog is not inclined to attack the person unless absolutely necessary. Therefore, your dog may bark, growl, show their teeth, or even lunge at the person. This is a scary reaction for you, as the owner, to deal with and can cause the people around you to become fearful as well.

To control your dog's behavior, you can teach your dog that they are safe with you by remaining calm and relaxed, removing them from the situation, and using commands like "leave it," "stay," and "sit." This will keep your dog calm, focused on you, and allow them to focus more on their commands than the person they dislike. 

Once you remove your dog from the bad person, replace your dog's negative emotions with something fun and happy. You do not want them holding on to their aggressive or fearful emotions. This will help train your dog to realize they are safe with you in all situations.