I have four ferrets, and two of are a little less social than the other. Only difference is one engages in play with the other ferrets, and is more playful than he used to be. However Daisy seems more interested in stealing things, and can get aggressive with things she seems to think are hers. She doesn't like being held like the others but is eager to use you to get out the cage. She does give kisses, but she can bite and get tempermental when she doesn't get her way.  She plays SOMETIMES  but mostly screeches and tries to once in a while scruff one specific ferret and the cats.