WASHINGTON (AP) — Researchers have discovered that some penguin parents sleep for only seconds at a time around-the-clock to protect their eggs and chicks. Sensors were attached to adult chinstrap penguins in Antarctica for the research.

The results published Thursday show that during the breeding season, the penguins nod off thousands of times each day but only for about four seconds at a time.

The parents need to stay vigilant to protect the chicks and nest sites from a large predatory bird and other penguins in the crowded colonies.

The researchers say these mini-catnaps appear to be enough to keep the parents going for weeks.