i also think seeing a vet would be a good idea. as for the nipping, my pionus has started acting like this as well when getting him out of the cage, or to put him away at night, it's just defiance, them trying to see how much they can get away with. If you show them you are in command and, not forcefully but strongly, tell them to step up, should help your problem if he does it again. he is young also, only 2 years old this spring. he is hand tamed and trained, just a silly boy trying to play games, almost like chase.
