What is considered just as important as physical exercise for keeping an Australian Terrier content?

Answer

Mental stimulation.

Because they are intelligent and have a natural drive to hunt or dig, mental stimulation is just as important as physical exertion to prevent unwanted behaviors stemming from boredom.

What is considered just as important as physical exercise for keeping an Australian Terrier content?
AustraliaDogcharacteristicbreedTerrier