Why does my cat bite me?

Cornell says some cats suddenly bite when petted, and names overstimulation and wanting to control when petting ends as likely reasons. VCA adds that a cheek rub may be scent marking, not a request to be stroked. (Cornell, VCA)

Warning signs before a petting bite

• Dilated pupils, tail lashing and ears moving back. (Cornell)
• Turning the head quickly towards your hand, freezing or a tense body. (ASPCA, VCA)

Stroke for 3 to 5 seconds, then pause and let your cat decide. To retrain a biter, VCA suggests one or two strokes, then “All done” and a treat for staying calm. (iCatCare, VCA)

Rough play is common and natural in kittens and young cats less than 2 years of age. Cornell says kittens not raised with littermates are especially prone. (ASPCA, Cornell)

• Never use your hands or feet to play with a kitten. Growing teeth and claws hurt. (iCatCare)
• Use a wand toy moved in jerky, random movements, and put it away after play. (iCatCare)
• Kittens taught to play with hands can grow into adults that injure their owners. (iCatCare)
• When play turns rough, walk away so your cat learns that biting ends the game. (Cornell)

A bite from nowhere often has a trigger you did not see. Redirected aggression happens when a cat is excited by something it cannot reach, and turns on the nearest person or cat. (Cornell, Merck)

• Common triggers: loud noises, a stray cat seen through a window, fights between cats at home. (Cornell)
• ASPCA calls it probably the most dangerous kind, because the bites are uninhibited. (ASPCA)
• Prevent it by removing or avoiding the trigger, such as lowering a blind. (Cornell)

It is also a sign of chronic stress. Our cat body language decoder helps you spot rising tension early. (iCatCare)

Fear causes many types of aggression. A frightened cat tries to avoid the threat but bites when it cannot escape, and a cat that learns biting works may use it more. (Merck)

• Look for a low crouch, tail tucked under the body, ears flat, hissing and bared teeth. (Cornell)
• Do not touch, try to reassure or punish. Leave your cat alone until it calms down. (ASPCA)

Yes. Pain aggression is a defensive reaction: cats in pain may bite to avoid touch or movement. Cornell lists hyperthyroidism, osteoarthritis, dental disease and nervous system problems among the causes of aggression. (Merck, Cornell)

A cat in pain may hiss when approached and bite when touched. If bites mostly come when one area is touched, VCA says think of pain. Contact your vet as soon as you can. (iCatCare, VCA)

1. Rule out pain and illness with your vet first. (iCatCare)
2. Let your cat start contact and decide how long it lasts. (iCatCare)
3. Keep strokes short, stop at the first warning sign, and give a cooling-down period. (Cornell)
4. Give play an outlet with wand toys. Cats are sprinters: one minute of frenzied play is a good result. (iCatCare)
5. Never punish. Painful punishment does not work and can trigger pain-induced aggression. (ASPCA)
6. Keep small children from handling a cat with a history of petting bites, since they miss the warning signs. (Cornell)
7. Start early: the earlier treatment starts, the better the chance it works. (Merck)

International Cat Care says anyone bitten by a cat should see a doctor straight away. VCA agrees: cat bites can be serious. (iCatCare, VCA)

First aid for a cat bite or scratch

1. Wash the wound with warm soapy water straight away (CDC).
2. See a doctor, who will clean the wound and may give antibiotics (iCatCare).
3. Get medical attention in particular if the cat’s rabies vaccination is unknown, the cat seems sick, the wound is serious or becomes red, painful, warm or swollen, or your last tetanus shot was more than 5 years ago (CDC).
4. Report an unprovoked bite from a stray, or from a cat whose rabies vaccination is unknown, to animal control or your local health department (CDC).

Bites can spread germs even when the wound does not look deep, and about 20% to 80% of reported cat bites and scratches become infected (CDC).

See your vet before trying to change the behaviour, so medical causes are ruled out first. Your vet can refer you to a qualified clinical animal behaviourist if needed. No source gives a number of bites or days to wait, so if biting is new or getting worse, call your vet to be safe. (Merck, iCatCare)

For more, see our cat body language guide, the behaviour hub and, as your cat ages, our cat age calculator.

Every figure and threshold on this page comes from the veterinary sources below, and each one is linked where it is used. Where no source gives a cut-off, we say call your vet rather than invent one.