Cats are also very aware of changes on their habitat and are kept in way too small space to express natural behaviour. Most house cats are extremely stressed. You can see this if you even move one bigger object in the house and watch how the cat gets anxious. The behaviour is much more complex than the human emotions we project to cats. They are different, we don't know how they feel. But most cats are not "happy", we just fail to see it and laugh when they run around and do stupid things out of boredom and stress. Edit: Also Stockholm syndrome... And would cats hang around humans if living in their natural habitat and not receiving food from humans? I don't know.. But the spectrum of "do they care about humans or not" is much wider than just that question.