13 ANIMALS THAT DO NOT SLEEP - Names, characteristics, photos and VIDEO

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Sleep, an action so necessary physically and mentally for humans. However, and within how surprising nature is, there are animals for which this activity that is so common to us, is not very necessary or, at least, does not require to invest so many hours in it.

From Ecologist Verde we present this article where we explain the peculiarities of several animals that don't sleep or that present a different pattern when it comes to sleeping or resting, compared to what we are used to, so we could say that they are animals that sleep little or different.


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 they 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 they sleep standing up, although sometimes, if they feel very safe, they lie down on the floor and rest their head on it, just in front of them, or on their back or thighs, thus resting their neck.

With respect to how much do giraffes sleep, they sleep between 30 minutes and 2 hours a day but, be careful, they do not do it continuously but 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.

Meet more Animals that sleep standing up in this other post.

The ants

Have you ever wondered: Do ants sleep or not?. Well, these insects present a characteristic cyclical pattern in which they rest 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 the ants they don't sleep like we do and other animals similar to us, but have their own method to be able to rest optimally.

Learn more curiosities about ants with this other post about How ants communicate.

The Sharks

Have you ever wondered if sharks sleep? Well the answer is that, due to their physiology, most species among sharks can't 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.

Here you can discover much more about this question: Do sharks sleep?


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 they can spend 84 hours without sleep, that is to say, between 3 days and 4 days, while they travel swimming in search of food. However, your reward is a good sleep that can last up to 19 hours in order to fully recover.

The flies

You may have ever wondered whether flies sleep or not, as well as other insects. Well 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 may be a long sleepless time Or better, sleeping in very short periods, from a few seconds to a few minutes and can be like this for several days, something that is very useful in times that need to be much more active for their survival and that of the species.

The elephants

Wild African elephants have been determined to be mammals that sleep less 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 sleep phase (rapid eye movement) every three to four days, falling asleep lying down instead of standing.


Horses can last all day in good condition and active with just sleep 3 hours in the evening. In addition, they can sleep both lying down and standing, thanks to a "fixation" device in the legs that blocks their knees to stay upright and still, which has evolved over time and that also have other types of animals, such as 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 of the animals that sleep little. In fact, they just fall asleep 4 hours a day and usually at night. Cows usually sleep lying down and with your head resting on your side or on the ground.

The sheep

Yes, sheep are another example of animals that sleep differently from us. They can sleep so alone between 4 and 5 hours at night, either standing or lying down. Their custom is to sleep inside the herd, while others remain awake and can alert to any approach of predators.

The donkies

Even if the donkies often have a reputation for being lazy animals, these animals only need to sleep, on average, a few 3 hours a day with a very short REM phase to reach 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

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

Animals that don't sleep at night

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, 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) can also be differentiated. As examples of animals that don't sleep at night, that is, they do it during the day and unlike species like ours, we have these two animals:

  • Deer, and several of his 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 don't do it at nightRather, when most animals are asleep at night, deer remain fully awake, preferring to be active when they are safer 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 are the Lions. Is about nocturnal animals, which exert the highest hunting activity during the evening and, therefore, tend to sleep during the day. Y, 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.

We encourage you to read this other article about nocturnal and diurnal animals: list of species and photos. In addition, in the video below you can see a summary about these animals that sleep in strange ways.

If you want to read more articles similar to Animals that don't sleep, we recommend that you enter our category of Animal Curiosities.

  • BBC News. (2022). Mysteries of elephant sleep revealed. Recovered from: https://www.bbc.com/news/science-environment-39126993#:~:text=Elephants%20in%20zoos%20sleep%20for,two%20hours%2C%20mainly%20at%20night.&text= They% 20only% 20went% 20into% 20rapid, rather% 20than% 20on% 20their% 20feet.
  • BBC Earth News. Reporting life on earth. (2009). The secrets of ant sleep revealed. Recovered from: http://news.bbc.co.uk/earth/hi/earth_news/newsid_8100000/8100876.stm
  • Cirelli, C., & Bushey, D. (2008). Sleep and wakefulness in Drosophila melanogaster. Annals of the New York Academy of Sciences, 1129, 323.
  • National Ocean Service. (2022). Do fish sleep?. Retrieved from: https://oceanservice.noaa.gov/facts/fish-sleep.html
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