Because they are so energetic, Jack Russels get bored easily if you treat them like a lap dog. They have developed a reputation for unruliness and mischievousness as pets, since two of the traits they were bred for, their loud bark and propensity for digging (once used to root foxes out of their hiding places), don’t mix well with family living. Jack Russels can be fierce fighters, and they often forget their size when going up against larger dogs; in New Zealand recently, five children were saved from an attack by two Pit Bulls by their family’s courageous Jack Russel.