Alleyoops-we have 4 outdoor male cats that love to come inside to use the litter box!!!!!!!! They think it's a treat!!!!!!!!! I catch them running in the house and going straight to the litter box. I hate to get onto them because one day they may need to stay in the house. Like if they get sick or when they are old enough to get neutered they may need to recover in the house. If I yell at them now for using the litter box they make think it's a no-no and not use it when I want them too!!!