Cute dog! I once knew a Jack Russell Terrier named Einstein as well, and his owner also had his half-sister, a female Jakc Russell named Emma Sue. Emma Sue was the ratter of the pair, and their owner said the girl Jack Russell would dig up gophers at the park and shake them until she broke their necks. A friend of mine said that's horrible, but if you're not a fan of rodents, you probably don't care. As for me, it's better than playing Whack-A-Mole with gophers.