The black cats are "predators" and the not black cats are "prey". The prey eat apples to duplicate and the predators eat prey to duplicate. If they don't eat, they will also die. There are certain mutations they can get like increased or decreased speed or eyesight. This thing is really unbalanced, so the predators pretty much always come out on top.
This is just something I was experimenting on a while back. I felt bad leaving it unshared for some reason, so I guess I'v sharing it, but I'll probably come back later and unshare it again.
