Sentinel At The Gate

It's getting near midnight and Charlie is sat at one of his numerous lookout points around the perimeter of the house. Other felines are his main concern, one in particular, Felix, who lives a few doors away. They don't get on well at all. Felix is just as unsociable as Charlie but he always turns up anyway just to annoy him and usually around 3am in the morning when we are asleep. The shrieks and hissing coming through the bedroom window alerts us to that fact. Why are cats so unsociable with each other? Come to think of it, we're not such different beings ourselves.