Sometimes it can be tough to tell if cats are playing or fighting, but a sure way to tell is by observing their body language.
Ways to tell if cats are fighting:
Hissing or Growling: when cats are playing, they don’t generally make much sound; they may occasionally meow but if there is hissing or growling, they may be fighting.
Ears back: When cats are playing, their ears are mostly upright or forward but if they are fighting, their ears may be turned back towards the head.
Claws out: when cats are playing, their claws are typically retracted but if they are fighting, their claws are likely out so they can cause harm.
Hair standing on end: when cats are playing, their coat is fairly relaxed but when they are fighting, they tend to puff up the hair on their body and tail to make themselves look bigger (also known as “Halloween Cat”).