I have heard bad reports about Jack Russell Terriers hyperness.Are they really that hyper? Or do they just need to have a good ,firm trainer(the owner!!!!) Because Lucy, our nieghbors Jackie, I love! She is a little hyper(tearing around the front yard, hyper) but really,even though she IS quite active,I don't really notice it when I walk over.I mean, she runs to great me, jumps up on my knee, (thats as far up as she can jump) What Im saying is that thier hyperness isn't as hard to deal with like a bigger breeds hyperness would be.I want to say, that they are actully really lovable and fun, as lond as you have, a good .firmness about you when training a Jackie. I just wanted to comment on these breeds.I really like them!