Repetition and positive reinforcement are key. Off-camera buzzers or clickers — which signify food is coming — summoned the cats to their marks on set.

A hellish shoot in the Canadian wilderness described repeatedly by "The Revenant" actor Leonardo DiCaprio wasn't exactly a walk in the woods for the film's veteran animal trainer either.

Forestry officials in Indonesia are training elephants to assist firefighter crews in putting out forest fires, and prevent them from igniting.