In humans, falling asleep for a few seconds during the day is a sign we need more sleep.
A new study published in November found that chinstrap penguins take short naps thousands of times every day. And the naps are about just four seconds each because they need to stay alert for threats.
Chinstrap penguins get their name for the thin black band of feathers around their heads that look just like a little strap.
Scientists think they are the most common penguin species, with almost 8 million penguin couples found mainly on the Antarctic Peninsula and South Atlantic Ocean islands.
When nesting, one parent penguin has to keep watch over the eggs, guarding them from predatory birds called skuas while their partners is away for days hunting for food.
They also have to defend their nests from other penguins that might try to steal materials for building nest. Once a penguin partner finally returns, the couple switches roles.
The researchers who did the study say this showed that lots of short naps can work too for some animals. For them, even small bits of sleep can add up and be useful (see graphic).
