The Chihuahua (Cookie) I bought from the Humane Society ( after MIL returned her there) is doing pretty good. She back slides sometimes and a fly swatter reminds her. She is settling down a bit. She has lots of bad habits, but, for the most part has stopped bothering my old toy poodles, they are 15-1/2 yr.s old - equal to a person in their late 80s, and they don't appreciate her boundless energy. I know time will help most of her bad behavior, she is starting to get use to all the other pets and that will help too. She will be 2 in August.