The most common type of aggressive behavior is play aggression, which is normal for all young mammals. For cats, play aggression includes stalking, pouncing and mock fighting. A young cat may hide in a corner and then stalk, chase and pounce on an object or person! Kittens normally play with each other, with their mother and with a variety of moving objects. If none of these are available, they will treat human arms and legs as playthings.
It's important to teach kittens an acceptable way to play appropriately from the beginning. If possible, take home two kittens so they can fulfill their need to play with each other. If this is not feasible, then direct the kitten to "fun" toys such as long strings with toys or feathers attached (don't let your kitten swallow it!) or ping pong balls. This will help minimize those secret ambushes and prevent you from becoming, in effect, a big squeaky toy. Always keep these toys, especially the ones with strings, away from your cat when you are not around to supervise. Many people misinterpret play as a sign of serious aggression. Playful cats "attack" silently and do not typically break the skin when they bite. Seriously aggressive and potentially dangerous cats often hiss or growl and bite more severely. Using a water spray bottle to keep the cat at bay is sometimes a helpful temporary measure. Hitting a cat is never recommended since it often causes a defensive reaction, may lead to aggression and is inhumane.
Inter-cat aggression is the second most common reason owners bring their cats to The Behavior Service. Cats may not co-habitate well for a variety of reasons, including incompatible temperaments, territorial competitions or as a consequence of overcrowding. Cats that have gotten along well for a long period of time may experience an abrupt falling out following a separation, such as when one cat is returned home after a visit to the veterinarian's office for treatment (non-recognition aggression) or when both cats are startled by an external stimulus and one cat attacks the other as a result of its agitation when, for instance, it views an intruding outdoor cat through the sliding glass door (redirected aggression).
Most of these situations require a gradual reintroduction paired with positive experiences to reunite the feuding felines. How long this process will take depends on a variety of factors, including the severity of the meltdown and the duration of the duress. Medication may facilitate your behavior modification efforts, but there are no magic pills and some management changes and training efforts will be required on your part.
It's important to teach kittens an acceptable way to play appropriately from the beginning.