I adopted a jack russell terrior mix about 4 months ago. He was about 6 weeks old when I bought him home. He is very loving when he finally calms down but he doesn’t let my lab or my blue tick eat in peace or play without him jumping on top of them. He growls and because very agressive with the other dogs. Is this “normal” for this breed? I must confess I did not do any research before getting him. My other dogs are so tame and loving I don’t know how much more I can take from the “wild beast”. He is not at all agressive towards any family members. Are they best suited for being in a one dog home? Also he is very hyper as far as jumping on you over and over again. How can he be trained not to do that? I have tried ignoring him and telling him to stop and sit but he just seems to jump even more.