Snowy Plovers sleep with the bill and the front of the head tucked under their feathers. While sleeping, they will only stand on one leg, especially when the weather is cold. Periodically, they will close their eyes while sleeping. Both sexes actively defend their nest territories by posturing, chasing, or fighting. This is done by running or flying at the intruder.
Males tend to be more aggressive than females.
Fights frequently occur between males when their broods are threatened. Adults may sometimes invade another plover's territory to peck their chicks when their own territories are invaded. During some fights, a bird may grab its enemy's tail with their bill and pull on its feathers while turning in circles. Snowy Plovers are a social bird in winter. Birds form flocks of up to 300 individuals.