I live with my parents and we have had 4 house cats for several years now. Two of our cats however started fighting suddenly and I am wondering if there is a solution to this.

The cats in question are Ferdinand and Evinrude.

A year or so ago for some reason Ferdinand began to start hissing at Evinrude whenever he came close to him. This lasted for a few weeks and then inexplicably stopped.

Well this event began again a month or two ago and has not stopped, rather it has escalated. It started out as Ferdinand would simply hiss and run away whenever he saw Evinrude within about 10 feet of him. But now Evinrude has, as a casual observer might deduce, taken this as a challenge and started rushing at Ferdinand which results in the two starting to fight. Nothing major as my parents and I break it up, and mostly it's the typical hissing, spitting, and rapid paw attacks until Ferdinand is able to run away and hide in a closet or under a bed.

We don't really know what to do, so if anyone knows of any solutions that would be very nice. The fighting between them isn't very serious, but it's still concerning since we obviously don't want them doing this. Plus at times it can make it to where Ferdinand stays in one room a lot more than usual.