Jack Russell terrier cross advice needed

[MojoWrkn]

8. I have two "holy terriers" and both display that shaking of their toys with vigor!

The older one is a Parson and he has caught/killed several slow squirrels that were in their fenced in yard but he doesn't maim them. He always brings them to the doggie door and leaves them intact. He is very obedient for the most part and when on walks, squirrels tempt him but I have a sound I make that stops him. He's not aggressive to cats but cats don't seem to like him. The other, younger dog is still a puppy and has learned many of the actions from his brother. He has not caught any squirrels and doesn't seem to be as interested in them as the older dog. They are so smart and so much fun and really keep me on my toes! I also have a x-minpin female and she really rules the roost! I'd have several Jacks if I could! They do need exercise and I do lots of enrichment activities to keep their minds busy.