Do you know which animals sleep with their eyes open?

A dream is very mysterious, causing a keen interest of scientists, a state that is necessary, as we imagine, for all life on earth. But is it? Are they all asleep? And what animals sleep with their eyes open? Let's take a look at them in the "bedroom".

So which animals sleep with their eyes open?

The first come to mind fish. They do not have eyelids, therefore their eyes are always open. In fact, no one was really engaged in the sleep of the fish, probably because it did not represent any interest for science. But marine mammals - dolphins and whales - were studied tightly. And the scientists found that they can not afford a dream in our understanding. Both dolphins and whales have to periodically pop up to breathe in air. Because of what they have in turn, sleeps only one of the hemispheres. And sharks in general need to be worn underwater, without stopping, since air can get into their blood, only if the gills are washed at high speed by water.

Does the cow sleep with your eyes open?

Wondering which animals sleep with their eyes open, many remember the giraffe. But this is not true! This myth is based, probably, on the feature that a giraffe can do without sleep for weeks. It is enough for him to take a nap during the day for 20 minutes, in order to restore strength. At this time, he puts his head between the thick branches of trees and, thanks to strong neck muscles, does not fall. And to sleep, the animal lies down and wraps its neck around the legs.

But the cows, sheep and horses sleep and stand, not closing their eyes, and lying down, lowering their eyelids. Obviously, they are forced to do this by the situation or mood. To sleep, they have four hours, and the rest of the time they just doze. By the way, it is at this time that the cow chews its "chewing gum". Similar movements of the jaw she does and during that part of the dream, which is called slow. And dreams and cows, and horses only see lying.

These animals belong to those who are able to sleep with the so-called "gregarious" sleep, during which animals are massively resting, and several individuals are vigilantly guarding their peace and bliss. Then the watchmen change.

Thinking about which animals sleep with their eyes open, people usually also call snakes that have merged transparent eyelids, and insects that do not have an eyelid at all.

For example, at the University of Pennsylvania, scientists have discovered how fly-flies fly. It turns out that they have a fairly long sleep - almost eight hours. The swarm of flies spreads at convenient places, and each individual, lying down on his abdomen and carefully turning away from food, falls asleep. And so: 5 hours per night and up to 3 hours during the day.

And what animal does not sleep?

Previously, it was believed that birds do not sleep during migration. But it turned out that this is not so. Every ten minutes one of the birds flies into the middle of the pack and sleeps there. It happens this way: it moves the wings only slightly, so as not to fall, but carries its airflow created with the help of the whole pack. Then the next bird will succeed her. But to catch the period when the cuckoo is asleep, it has not yet been possible. She day and night is in "trouble".

Bees are also in constant motion. Probably, they somehow rest, it just happens in a very short time or too rarely.

Also the notion of ants has changed. They were formerly considered to be animals that never sleep. But it turns out that they sleep almost 4 hours a day. Just fall asleep ants 250 times and at the same time they sleep 1 minute. By the way, waking up, they even stretch!