Whether you are an early bird or a night owl, your sleeping habits as a person are still a lot more normal than those of some animals. When it comes to humans, our resting habits are very simple: we like to sleep at night when it’s dark and quiet. Some other animals, however, have very interesting sleeping habits.
Dolphins sleep with one eye open.

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Not only do dolphins and other cetaceans sleep with one eye open, they keep one side of their brain awake as well. This happens because these animals live in water and need to keep moving so their bodies don’t cool down. So while one side of dolphins’ brains is sleeping, the other is awake keeping their bodies in movement.
Parrotfish sleep inside a bubble.

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Just like we want a peaceful environment when we go to sleep, parrotfish seek the same tranquility when they need to rest. These animals emit a secretion that becomes a bubble around their body, almost like a sleeping bag. This bubble is used to prevent crustaceans from bothering parrotfish while they sleep.
Giraffes, elephants and horses sleep standing up.

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While we would much rather sleep lying on a bed, some animals can easily sleep standing up. Animals like giraffes, elephants and equines have a mechanism that holds their knees in place, allowing them to relax and sleep standing on their feet. This is useful because these animals need to constantly be prepared to run away from predators.