Do Some Animals Leave One Eye Open When They Sleep?
Sleep is the main need for every living thing in the universe. However, not all animals will like the humans. The timing of sleeping the way of sleeping differs from human beings. For example, the elephants and giraffes will sleep for two to four hours, where as bats, apogees will sleep above twenty hours. In winter, the animals, which go to winter sleep for weeks and some for months continuously. Some animals will sleep by standing; some animals will sleep by hanging to the branches.
In sleep, there are two types, one is good sleep, and other is rapid eye moment (REM) sleep. In first type of sleep, our brain also takes rest, where as in second type of sleep the brain works as sharp as when we awoke. Along with these two types of sleeps, there is another variety of sleep in that the animal’s half brain will takes rest the other half brain will works. In this type of sleep, the animals will open one eye when they sleep. For example, dolphins, whales etc will sleep with one open eye. At the same way the ducks, which are outside of the group, will sleep with one open eye and with half brain working.