I've got seven cats, two are outside only, four are in-and-out, and one elderly ill cat is inside only. The outside cats have to be out because they fear being inside. One related to them is tame because I more or less tamed her while still young...she chose to start staying in at night one very very cold time. The other three were kittens (now over 1.5 years) abandoned at about one month old. Unfortunately, Little Kitty, one of the outdoor kitties can be mean and really hates the three youngest cats. There have been fights...I hate that! Sometimes she's outside the window and one or more of the youngest ones are inside the window and they try to fight through the window...at least, nobody gets hurt that way!