For male Adelie penguins, part of attracting a mate is building a good-looking nest. To build their nest, they need to gather stones, which they then pile together.
Like any guy trying to impress his lady, it's a challenge to find the best possible rocks for their nest. What's worse, it can take a long time, as penguins carry the rocks in their beaks, one by one, back to their nests.
Some penguins cheat the system, though. There are some who will wait for a fellow penguin to leave to get another rock. The thief then takes the rocks from that penguin's nest, barely waiting until the victim has turned around before doing so.
The non-criminal penguins never even seem to notice this happening. The criminals tend to keep a close eye on their own nests, however. No honor amongst thieves, after all.
Guess it pays to be a criminal in Antarctica, while the nice guy really does finish last.
