National Geographic takes a look at some of the unusual sleeping habits of animals like walruses, bats, hippos, and more. Some animals sleep for hours on end while other animals only put half their brains to sleep at a time
National Geographic takes a look at some of the unusual sleeping habits of animals like walruses, bats, hippos, and more. Some animals sleep for hours on end while other animals only put half their brains to sleep at a time