Playing or Fighting?

It can be difficult to tell the difference sometimes between cat play
or fighting. The following are a few general guidelines to help you
determine which is which:

• Play fighting is often silent – no yowling or screaming should be present in play.
• Cats who play with one another tend to take turns in the offensive
  and defensive postures. While engaged in fighting, there’s usually no
  role reversal.
• The biting is gentle and causes no injury or pain to the recipient and
  the claws are usually retracted. There is no reason to break a play
  fight if it continues at this level.
• When cats are playing, they may each hiss once or twice, but if your cats hiss several times, most likely they are fighting.
• Cats should not get hurt during play, unless it’s by accident. Cats fighting may give or receive bite or scratch wounds.
• When your cats are done playing there will be a rapid recovery to normal and no obvious tension between the pair. They should be acting normally with each
  other, not avoiding each other. After fighting, one or both of the cats
  will tend to stay out of each others way.
• If you have cats who don’t tend to get along with each other and
  they look like they’re playing, they may actually be fighting. If you
  are not sure, try to distract them with a positive noise, like the can
  opener or shaking the treat box. Be sure to keep it positive; you don’t want to discourage a possible friendship if they really are
  playing.