Also animals act different when away from their owners. For example, a dog I have right now is friendly with other dogs with her mum, but has been a nuisance charging at other dogs, growling, stealing their toys, and just being a dick when she's with me, to the point I have to put her in a separate room to play with my dogs. How do we know this cat is going to remain chill, friendly, and keep to himself with a new person in the environment. New schedule, any small changes can change a pets behaviour.