Animals that do not sleep

They are very common in our day to day, but we still have doubts about them, such as: do fish sleep? . The truth is that fish that do not sleep in the same way as land mammals, the vast majority of them only rest or sleep superficially .

This is because the fish reduce their activity and metabolism while at the same time keeping an eye out for any possible danger. This process of rest or “suspended animation” is done by floating, digging in the sand to make a safe place or hiding among the corals.

As you could imagine, these animals sleep standing up , although sometimes, if they feel very safe, they lie down on the ground and rest their head on it, right in front of them, or on their back or thighs, thus resting their neck.

Regarding how much giraffes sleep , they sleep between 30 minutes and 2 hours a day but, be careful, they do not do so continuously but rather they are distributed in periods of between 5 and 10 minutes . The modality and the time that the giraffe spends in sleeping is to avoid being an easy target for its predators.

The ants

Have you ever wondered: do ants sleep or not? . Well, these insects present a characteristic cyclical pattern in which they rest for 8 minutes every 12-hour period ; However, even if they have two of these rest periods every 24 hours, only one of them would be comparable to the definition of sleep and is equivalent to a deeper rest phase, with a much lower jaw and antenna activity than the other period. So, we can say that ants do not sleep as we and other animals similar to us do, but that they have their own method to be able to rest optimally.

The Sharks

Have you ever wondered if sharks sleep? Well, the answer is that, due to their physiology, most species among sharks cannot sleep , at least they do not rest deeply or stay still . This is because to obtain oxygen they need to be in constant movement so that the water enters through their gills, since they do not have an organ that performs this function. To get some rest, what they do is place themselves in areas of ocean currents that allow them to combine certain moments of low activity.

Walruses

Walruses seem deceptive when it comes to how long or how they sleep, as they go from one extreme to the other. These marine mammals can spend 84 hours without sleep , that is, between 3 and 4 days, while they swim in search of food. However, your reward is a good sleep that can last up to 19 hours in order to fully recover.

You may have ever wondered whether flies sleep or not, as well as other insects. Yes, flies usually sleep at night , although sometimes they take a little nap during the day, since they prefer the heat and the sun. In many species, while females sleep between 6 and 13 hours, males sleep more hours, specifically, between 13 and 18 hours.

However, some species can go a long time without sleeping or, rather, sleeping in very short periods , from a few seconds to a few minutes and can stay this way for several days, something that is very useful in times that need to be a lot more active for their survival and that of the species.

Wild African elephants have been found to be the sleeping mammals for the shortest time . In contrast to the elephants that live in zoos that can sleep between four and six hours a day, when they are in their natural habitat, they usually sleep a maximum of 2 hours , usually at night.

However, if they find themselves in a dangerous situation, they can stay awake for 48 hours or several more days, depending on the situation, taking advantage of this time to travel long distances and escape predators, hunters or other dangers. Thus, they only enter REM ( rapid eye movement ) sleep phase every three or four days, falling asleep lying down instead of standing.

Horses can last all day in good condition and active with just 3 hours of sleep at night. In addition, they can sleep both lying down and standing up , thanks to a “fixation” device in their legs that blocks their knees to stay upright and still, which has evolved over time and that other types of animals also have. , like other large mammals or even some birds.

Although the sleep of cows is important for milk production, and therefore those that are nursing calves try to sleep more, these are other animals that sleep little . In fact, they only fall asleep 4 hours a day and usually at night. Cows usually sleep lying down with their head resting on their side or on the ground.

Yes, sheep are another example of animals that sleep differently from us. They can get to sleep as little as 4 to 5 hours at night , either standing up or lying down . Their habit is to sleep within the herd, while others remain awake and can alert to any approach of predators.

Although donkeys often have a reputation for being lazy animals, these animals only need to sleep, on average, about 3 hours a day with a very short REM phase to achieve all the energy they will need throughout the day. Like several of the aforementioned animals, it is because in the wild they are prey to predators and they need to spend a lot of time alert to survive.

The ostrich’s way of sleeping is peculiar, and no, it is not that it sleeps with its head buried in the sand as some myths say, but that they remain with their eyes open while they sleep . This allows their brain to rest while remaining alert. These flightless birds can spend between 6 and 7 hours a day sleeping.

Thus, there are different types of behaviors regarding sleep and rest among animals. For example, there are not only those who sleep more or less hours, but there are also those who sleep stretched out on the floor and / or standing up, with their eyes open or closed, always moving or totally still, etc. Likewise, it is also possible to differentiate between those that sleep at night (which are diurnal animals or with activity during the day) and those that sleep during the day (which are nocturnal animals or with activity at night). As examples of animals that do not sleep at night , that is, they do so during the day and unlike species like ours, we have these two animals:

• Deer , and several of their relatives, are another example of animals that sleep little , since these mammals only allow themselves to sleep about 3 hours a day. However, in addition to this, they do not do it at night , but when most animals are asleep at night, deer remain fully awake, since they prefer to be active when they are safest and have less risk of predation, thus taking advantage of the darkness as protection from predators.
• Another example of this type of sleep in animals is lions . They are nocturnal animals , which exert the highest hunting activity during the evening and, therefore, tend to sleep during the day. And how much does a lion sleep? Much! Males sleep between 18 and 20 hours a day, while for females the hours of sleep oscillate between 15 and 18 hours. However, when we talk about zoo lions, the hours are reduced between 10 and 15.