Why Does my Cat Bite For No Reason?

Jane MillerCat Health1 Comment

Why Does my Cat Bite For No Reason - SweetieKitty

Last updated: January 10, 2020

Well, why do they? This cat is fed, watered, sheltered, loved and given the best medical care money can buy. So why do cats bite the hand that feeds them? What motivates these little so-and-sos to be so aggressive?

The Biting Tools

Cats are obligate carnivores. You can tell that by the shape, size and number of their teeth, a dead giveaway being the disproportionately long fangs in their upper and lower jaws. In fact, a cat can’t quite close his mouth over them – a bit like a vampire! They have thirty adult teeth and twenty-six baby ones, fewer than humans and dogs. Cats have no grinding surfaces on their teeth at all; these are only necessary on plant eaters, and cats have evolved to eat meat and meat only. (Although domestic cats can do well on good quality dry cat food.) They may be small, but they have the same killing instincts as lions, leopards, and tigers, but in a domestic situation, this aggressive behavior is out of place. (Don’t tell them that, though; you’ll ruin their street cred!) So why do cats bite?

Maternal Aggression

Well, first of all, there is maternal love. I am a mother myself. When you become a mother you feel the fiercest kind of love possible. You would kill for your children and you would die for them. Any mother of any species would do the same and cats are no different. Don’t ever come between a tiger and her cubs or a cat and her kittens, and don’t start a fight with a mother cat. You will not win!

When Mommy cat gives birth, smelling, seeing, hearing and touching the new kittens causes the release of oxytocin, the so-called “mothering” hormone, which bonds mother and babies in a tight family unit. As well as this, the levels of the pregnancy hormone progesterone, which has a calming effect, go down quickly as the amount of estrogen rises. So the cooling-down properties of progesterone gradually diminish and the stimulating effects of estrogen increase. As soon as the milk-producing hormone, prolactin, kicks in, maternal aggression rises. So you have this gorgeous little nest of kitties and this normally biddable and sweet-tempered Mommy cat ready to fight to the death for her family. Why do cats bite? Because the first weapons in their arsenal are their teeth!   

Why Does my Cat Bite For No Reason - Angry Cat - SweetieKittyMale Aggression and Biting

I’m TESTOSTERONE TOM!  This means that I’m big, strong and manly. In fact, I’m mad, bad and dangerous to know, so all parents with girl cats, please lock up your daughters! Because I will fight to the death any other tomcat who dares lay a paw on my sexy queen!

This is the typical male attitude across many species (sorry guys) and cats are worse than most. Not only does testosterone make male cats bite and fight, it’s also responsible for that “scent” that female cats love and humans hate!

Get Him Fixed!

Please don’t think castration is cruel. It’s not; you’re doing him a favor! If not castrated, your average tom may neglect his grooming, and his appearance suffers (pul-eeze! This is OUTRAGEOUS!!!) This can cause a condition called “stud tail” when greasy deposits collect at the base of the intact tom’s tail. As well as this, he has less time for his human family because his mind is always on sex and fighting. Male cats wander in search of females to mate with, so in order to control the population and safeguard your tomcat, it’s best to let your vet castrate him before your neighbor does it with a carving knife! If not, it means that any other tomcat venturing onto your intact tom’s patch will find himself on the sharp end of your cat’s fangs, and vice versa. Cat bites are like injections but with nasty noxious bacteria instead of healing medicine. So it’s better to nip this in the bud and castrate him early, in fact, the younger the better. Hopefully, this will solve the problem.

Play Biting

When kittens are at their most playful, they do a lot of rough stuff! Scratching, biting, cuffing, smacking, stalking, pouncing and hissing at his brothers and sisters are all in a day’s play for this tiny carnivore. This is normal since the young cat is practicing and refining the skills he needs to hunt and kill prey for food. They begin this style of play early on in their development and even do it with Mommy! (So glad I’m not a cat Mommy!) Don’t worry, it’s not real aggression, it’s not aimed at you, and the kitty doesn’t mean to hurt anyone. He’s just being a cat!

Within the litter, if one kitty becomes too aggressive and bites too much, his opponent may growl, swat at him or walk away. Mommy might even join in with a swipe of her own. This is how kittens learn to “play nice!” If biting and swatting become too hard to handle nobody will want to play with him! Boo-hoo!

Petting Aggression

Like us, cats have different personalities. Some cats are sociable and polite and enjoy being petted and stroked for a long time. Some cats enjoy a bit of rough and tumble. They are extroverts and love the attention, but after a while, even though they asked for all this petting, playing and stroking, they get tired of it and tell you in their own unique feline style: “OK, that’s enough now. Back off and leave me in peace.” A cat in this mood will often bite or scratch, and this is your signal to just give him some space. Cats are not dogs, who’ll do just about anything to please you. They are their own special selves, and we like them that way!

Why Does my Cat Bite For No Reason - Cat Lying on the Ground - SweetieKittyOther Reasons for Biting

Redirected aggression

This type of aggression happens when the cat is stimulated by something, for example, a bird outside the window, and something comes and gets in the way. Just. Back. Off. Slowly. Give him time to calm down and he’ll be fine.


This is fairly obvious. You and I know what when it hurts you don’t want anyone to touch it. A cat can’t tell you this, so biting is his way of saying: “Ow! I’m sore!”


Every cat is an individual personality. Some cats run away, some hide, some freeze or lose control of their bladder and bowels. Some cats bite, hiss, growl, puff up and bite when they’re scared. If you have a scaredy-cat who does this, leave him alone to calm down. If it happens often, see your vet and if necessary a cat behaviorist.

So the bottom line is: neuter your males, handle your kitties gently, don’t get between Mommy and kittens, but above all else always, always love them!