Enlarge / Kittens engage more frequently in reciprocal wrestling ("play-fighting") compared to adult cats, a new study found. (credit: Getty Images) Anyone with more than one cat in the house knows that the occasional spat or outright cat fight is going to happen. But sometimes it can be tricky to determine whether cats are fighting or just playing rough, because the interaction could feature trademark behaviors of both, according to a recent paper published in the journal Scientific Reports.