Ah, yes, the joys of rival pet interactions! Tommy (my cat) and Snowball (trying to be my cat) love each other outside, and never fight. Inside, Snowball still loves Tommy, but Tommy is conflicted. On the one hand, it is sometimes fun to have Snowball inside to play with. On the other hand, Tommy's servants have been caught PETTING Snowball - he doesn't care that his food is sometimes stolen - there's more where that came from. So at least a couple times a day, if Snowball is in for a warm up and a learning session in being a tame cat, Tommy takes it into his head to beat the snot out of the smaller cat, and won't stop until I intervene or Snowball starts crying. Worse'n kids.