Did you know that ducks sleep with one eye open?
Studies have shown that ducks can allow half of their brain to sleep at a time. The half of the brain on the side of the closed eye sleeps, while the other half, with the open eye, remains alert.
Ducks living in risky conditions are more likely to sleep with one eye open to look out for predators.
Ducks have also been known to work together, and the ducks sleeping at the edge of the flock will keep their outwards eye open.