Should Dog Owners Worry About This Behavior?


The muzzle grasp is an interesting behavior that I’ve seen in many canids, including our domestic dogs. It’s a behavior that scares many dog owners who believe it signals unconditional and uninhibited aggression. It doesn’t. The muzzle grasp is yet one of those fascinating behaviors, which developed and evolved because it conferred a higher fitness to those who practiced it.

The function of this behavior is to confirm a relationship rather than to settle a dispute. The more self-confident dog will muzzle grasp a more insecure one and thus assert its social position. The more insecure individual does not resist the muzzle grasp. On the contrary, it is often the more insecure that invites its opponent to muzzle-grasp it. Even though we sometimes see this behavior at the end of a dispute, wolves and dogs only use it toward individuals they know well (teammates) almost as a way of saying, “You’re still a cub (pup).” The dispute itself does not tend to be serious, just a low-key challenge, usually over access to a particular resource. Youngsters, cubs, and pups sometimes solicit adults to muzzle-grasp them. This behavior appears to be reassuring for them, a means of saying, “I’m still your cub (pup).”

When used to settle a dispute, a muzzle grasp looks more violent and ends in most cases with the muzzle-grasped individual showing what we ethologists call passive-submissive behavior, i.e. lying on its back.


The muzzle grasp behavior emerges early on. Canine mothers muzzle grasp their puppies (sometimes accompanied by a growl) to deter them from suckling during weaning. At first, her behavior frightens them and they may whimper excessively, even if the mother has not harmed them at all. Later on, when grasped by the muzzle, the puppy lies down right away with its belly up. Previously, it was assumed that the mother needed to pin the puppy to the ground, but this is not the case as most puppies lie down voluntarily. Cubs and pups also muzzle grasp one another during play, typically between six and nine weeks of age. A muzzle grasp does not involve biting, just grasping. This behavior helps develop a relationship of trust between both parties: “We don’t hurt one another.”

Domestic dogs sometimes approach their owners puffing to them gently with their noses. By grasping them gently around the muzzle, we reaffirm our acceptance of them. We show self-control and that they can trust us. After being muzzle grasped for a while, the dogs will usually show a nose lick, maybe yawn and then walk calmly away. It’s like they are saying, “I’m still your puppy” and the owners replying, “I know and I’ll take good care of you.” Yawn back and all is good.

Sometimes, the dog may even grasp our hand or our arm ever so lightly with its mouth. That is not mouthing or biting at all. It’s a derivative of the nose puffing behavior, and it has the same function. We see a similar behavior between related adult dogs and pups and dogs that know one another very well. It is an invitation to interaction, bonding, and maybe a muzzle grasp. Again, pull your hand or arm gently away from the dog’s mouth, muzzle-grasp it for a little while, make a few chomping sounds and yawn. Speaking dog language helps promote an understanding between our dogs and us. It may make us look silly, but who cares? I don’t—do you?

The behavior of grasping our hands is under control of what Lorenz called “bite inhibition.”* Bite inhibition is the behavior displayed by a dog (and also other carnivores like the cat) when it restrains itself from biting an opponent, although it would be easy for it to do so. In such a situation, most dogs will limit themselves to grasping the opponent without causing damage.

Biting and mouthing are quite different. They are more forceful and challenging than the grasping of our hand as an invitation to a moment of affection, and we should not reinforce these behaviors at all.


In conclusion: dogs don’t have hands, and so they use their mouths to perform some functions for which primates use their hands. Hands can be aggressive and forceful, as well as gentle and affectionate, and so can canine mouths. We must not be blind to the subtleties of behavior. Life is not black-and-white—rather more of a rainbow, I’d say.


* Lorenz, K. (1949). King Solomon’s Ring (PDF). Routledge. Retrieved 2014-10-28.


Dogs showing the muzzle grasp behavior (photo by Marco de Kloet).


Muzzle grasp in adult wolves (photo by Monty Sloan).


Cubs and pups muzzle grasp one another during play (photo by Monty Sloan).

Mouthing and biting are not even remotely related to the muzzle grasp behavior. This photo shows clearly puppy play behavior, and yet it is biting. We should teach the puppy right away that this is not acceptable behavior (photo by unknown).


This behavior is not biting. It is a derivative of the muzzle grasp behavior and it functions as pacifying behavior. Photo: Ana Laura Chavez.

Featured image: A moment of social interaction: human uses her hand and dog uses its mouth. This is not a dog bite. Photo: Ana Laura Chavez.

Featured Course of the Week

Dogs and Children Dogs and children are wonderful together when all goes well. Learn how to prevent serious problems and how to motivate your child and dog to play safe, fun and meaningful games so that they can create a respectful relationship.

Featured Price: € 40.00 € 20.00

Learn more in our course Ethology. Ethology studies the behavior of animals in their natural environment. It is fundamental knowledge for the dedicated student of animal behavior as well as for any competent animal trainer. Roger Abrantes wrote the textbook included in the online course as a beautiful flip page book. Learn ethology from a leading ethologist.


Why Does My Dog Eat Poop?


Why do dogs eat their own poop? That’s an interesting question and I find on the Internet one horrendous explanation after the other, which the authors could avoid with a 101 course in Evolution. Even scarier is to read some rebuttals of perfectly scientifically valid accounts because of blatant ignorance.

That is why we offer our course ‘Evolution’ free of charge.

I will give you now two examples of how a bit knowledge of evolutionary biology can help you analyze statements and avoid making claims that don’t make sense or are very unlikely to be true.

Why does my dog eat its own poop? Here are some popular answers I found on the net.

Explanation 1: The dog knows that fewer predators will pay it any attention if there is no evidence of his having been around.

Is this probable? First, adult canines in nature are not particularly predated by any other species. They tend to defecate where that can, sometimes even using it to scent mark their territory, which is anything but concealing it. The only occasion where this occurs is when canine mothers eat their puppies’ feces while they are still in the den. The function of this behavior is to keep the den reasonably clean, free of parasites, and probably also odor free. Evolutionarily, those that didn’t do it suffered more cases of their progeny succumbing to disease. It might also have reduced the scent signature of the den helping it remaining concealed, but again that would only have been an advantage where predators with a reasonable sense of smell would share the same environment. It might have been beneficial for the Canis lupus lupussharing their environment with bears (family Ursidae).

Conclusion: it is unlikely that dogs eat their poop to conceal their whereabouts from predators except for mothers consuming their puppies’ feces.

Explanation 2: He (the dog) knows that removing the evidence means no punishment for inappropriate elimination.

Is this probable? To be true, it requires that the dog associates the feces with the punishment. How probable is it that the dog associates its act of defecation with the punishment from the owner arriving at the scene maybe 1-8 hours later? Natural selection has favored associations broadly spaced in time, but only for vital functions, like eating poisonous substances. There is evidence that the organism retains a kind of memory of anything that made it sick even occurring many hours later. However, we cannot envisage any situation in which it would be unconditionally and evolutionarily advantageous for an animal to associate defecating with a non-lethal punishment inflicted by some other animal. Natural selection would only favor it if its achieved benefits would exceed its costs grossly. It is true that insecure animals tend to keep a low profile, also restricting their urination and defecation to less-prominent locations, but not by eating it.

Conclusion: it is definitely possible to condition an association between feces and punishment, but I doubt we can teach any dog to eat its feces to avoid punishment. There is no evidence that eating own poop has been evolutionarily advantageous.

When analyzing a behavior, the evolutionary biologist asks: (1) what condition in the environment would favor the development of such a trait, (2) what conditions would favor its propagation into the population, (3) do the benefits of such a trait outweigh its costs both short and long-term?

Why do dogs eat their own poop, then? I have found a few plausible explanations but none conclusive, yet. Therefore, my answer must be, “I don’t know.” You may need to around. You are, now, in a better situation than earlier to evaluate any answer you may get because you know how to analyze an argument from an evolutionary point of view.

Featured image: Canine mothers (in wolves, African wild dogs, and domestic dogs) eat their puppies poop when they are still in the den. The function of this behavior is to keep the den fairly clean, free of parasites, and probably also odor free (Photo by Monty Sloan).