What makes your darling, sweet cat companion switch from snuggly to snarly when visitors arrive? Why is it your friends and family never see the “real” kitty you live with? And, is there anything you can do to change it? Many cat owners keep their pet indoors at all times to keep them safe and healthy. By staying inside, cats are protected from predators, vehicles and diseases — which is a great thing. But one potential downside to the situation is that indoor cats may live in a small “territory” with very little variety from day to day. We all get used to standard things in our environments, and expect some consistency. Some of us are more accepting of change, and some are not. Cats are no different. We know one reason for differences in acceptance of new things is being exposed to new things (scientists and animal trainers call these “novel stimuli”) during certain periods of development when the animal is more “open” and accepting to learning. For kittens, that period is the ages between 3 to 8 weeks. Kittens who are kept away from people and do not get early exposure may start life with a deficit for accepting strangers. Additionally, past experiences with people will have an effect — pleasant experiences make cats think people are good, and less happy experiences may make cats afraid of new people. Not all kittens are given opportunities for multiple safe encounters with people at that early age. Consequently, many cats are undersocialized, which means they are not comfortable with new or unusual things. A cat who lives with just one, two or only a few humans may find several new humans very frightening.