Why are we fighting when we could be napping?

Fighting takes a lot of energy, and napping is wonderful. I have a lot of tension in my house between my cats that don’t get along. It’s frustrating feeling like I have to monitor their interactions all the time, but since cats sleep around 18 hours a day (mine may sleep more) it’s just about the laziest sort of warfare you could ever imagine. Their mutual distrust is not enough to actually keep them awake, and I’ll find my cats positioned in what started off as a standoff and ended up with both of them sprawled out sleeping for several hours straight. Man, it’s so hard being a cat.