Initially used for fox hunting, the JRT has become a popular family pet because of their intelligence, short and easily maintained coat and effervescent personality.
However, because of their origins, like the Aussie, Jack Russells require high amounts of exercise and mental stimulation.
JRTs like nothing better than a good chase and will actively seek out smaller animals, occasionally leaving a trail of destruction during the mad chase. Some will even pick fights with other dogs twice their size.
In spite of their small size, their aggression, muscular compact build and single-mindedness can make them almost impossible for children to manage.