a interesting fact about ducks is that they have a unique way of sleeping called "unihemispheric slow-wave sleep." This means that ducks can rest one half of their brain while keeping the other half awake. This allows them to stay alert for predators even while sleeping. Ducks will often sleep in a row, with the ducks on the ends keeping one eye open and the brain hemisphere opposite to that eye awake, while the ducks in the middle can sleep more soundly. This remarkable adaptation helps ensure their safety in the wild.