We already know that cats will steal anything that's not tied down. But what about the rest of the animal kingdom? The tendency to steal food is a beneficial adaptation for a species, and taking what another critter has is not really rare. For example: Flowers produce nectar to attract bees for pollination purposes, but bumblebees take nectar from flowers without pollinating the plants in exchange.
Bees who’ve evolved with short tongues and thus can’t reach for the sweet nectar have learned to carve holes into the side of a flower in order to reach their reward. This phenomenon, first observed by Charles Darwin, gets a bee nectar without the bee pollinating the plant. More cannily, there’s evidence suggesting that bees aren’t born behaving this way—they learn how to thieve from other bees, a sad sign that bee society is being overrun by hoodlums.