This does mean they are tenacious and fearless pooches, with alert minds that need a lot of activity to keep satisfied. This tough terrier is pretty hardy and has a high prey drive because they were historically bred as hunting dogs.
They’re super smart and can have a stubborn streak, so although you can teach your JRT a whole repertoire of tricks, you might have to convince them to show them off. Like many terrier breeds, the Jack Russell is a small breed with a big personality.