The young ones tend to sleep more than adults do. Similarly, they can also sleep while standing or lying down. Just like giraffes, they are capable of sleeping for short bursts that last for around 15 minutes. Horses have the ability to sleep for only two hours in a day. In captivity, dolphins can enter a state of complete sleep while a tail reflex action keeps their blowhole above water. Therefore, it falls to the mothers to ensure that they do not go to sleep, which is why adults are able to go for at least a month without sleeping. Instead, they rest by pressing their bodies against their mothers so that they do not drown. For some dolphins, they do not go to sleep in the first month of their lives. Generally, dolphins go to sleep with only one side of their brain so that they use the other side of their brain for swimming and to watch out for predators. Experts sometimes describe this position as paradoxical sleep, that is, a state where the animal is resting but there is rapid eye movement as well as reduced muscle activity. This form of sleep is usually characterized by the animal bending its neck and bringing its head to a rest on the thigh or the hip. The animal also has irregular sleep phases where the giraffe can enter into deep sleep. Standing sleep is particularly common among older giraffes. During sleep, the animal may lie down or stay standing. In captivity, giraffes have been known to sleep for between four and five hours, which is mostly at night. Sometimes, people fell asleep while driving and that is really dangerous! Obviously, the scientists decided that not sleeping is bad for your health.Giraffes usually sleep, although not for long periods. The scientists also found that sleep-deprived people got so tired they fell asleep no matter what they were doing. In studies where people went without sleep, they found that people became half-awake, kind of like zombies walking around mindlessly. The first column looks at animals that meet the definition of sleep, the second column looks at whether the animals make up their sleep and the third column talks about why the animals were considered special cases.ДЇinally, scientists looked at whether not sleeping has serious consequences. Here is a table from the original article that lists all the animals the scientists thought were examples of not sleeping or not using rebound sleep. This was problematic because many animals regulate sleep by sleeping deeper, not longer, so they ruled out the research as proof of animals that donвЂ™t need to make up sleep. Yet, the scientists decided the experiments done were flawed because only the length of sleep was tested, not the quality of sleep. They found a few animals like bees that seemed to not need extra sleep. Next, scientists looked for animals that didnвЂ™t need to catch up on sleep after being awake for a long time. Animals that show harmful side effects from sleep deprivation (humans).Animals that don't need rebound sleep after using up all their energy (bees).Animals that don't need sleep (bullfrogs and dolphins).

The scientists looked at three different ways that animals sleep to see if it is true that some animals really don't need sleep. The scientists defined sleep as being still and having little to no reaction to attempts to awaken. With multiple ideas about why animals sleep, first scientists had to decide what counts as sleep. Maybe sleep is just a nice pastime вЂ“ like playing baseball or watching television вЂ“ that is useful for keeping us out of trouble but not necessarily for good health. Scientists are looking at a variety of explanations.

Many scientists believe that sleep serves a really important purpose but they havenвЂ™t found what that purpose is yet. Sleep seems to be common sense for keeping bodies healthy.

Practically every animal sleeps in one way or another. In the PLOS Biology article, вЂњ Is Sleep Essential?,вЂќ scientists discuss whether sleep is necessary for all species, and if so, why sleep is so important. Have you ever wondered how fish and dolphins sleep? Or why your best friend likes to sleep for 12 hours when you would rather sleep for eight hours? If you have, then you are in good company because many scientists have wondered the same thing.

Animals that dont sleep