Facts about the animal kingdom

How Do Otters Sleep?

Nick A. Romero
By Nick A. Romero, Biologist and environmental educator. May 3, 2023
How Do Otters Sleep?

Otters, those fascinating and lovable creatures of the water, have captured the hearts of many nature enthusiasts. They belong to the Mustelidae family, which includes various species like sea otters, river otters, and giant otters. As semi-aquatic mammals, otters have successfully adapted to their watery habitats, and their sleep patterns are closely linked to their aquatic lifestyle. While we admire their graceful movements and adorable appearances, have you ever wondered how otters actually sleep?

In this AnimalWised article, we will explore how otters sleep and uncover their unique behaviors and adaptations that enable them to live and thrive in aquatic habitats.

You may also be interested in: How Long Do Otters Live? - Otter Lifespan


  1. Where do otters sleep?
  2. How do otters sleep?
  3. When do otters sleep?

Where do otters sleep?

To understand how otters sleep, it is important to consider their natural habitat. Otters are predominantly aquatic animals, inhabiting environments such as rivers, lakes, estuaries, and coastlines where they can find an ample supply of fish, their primary food source. With their streamlined bodies and webbed feet, otters are remarkably adept swimmers, effortlessly navigating through the water.

The sleeping habits of otters are influenced by their species. Among the recognized 13 species, two notable species are the sea otter (Enhydra lutris) and the marine otter (Lontra felina). The sea otter primarily resides in marine environments, while the marine otter is another species that inhabits coastal marine habitats. The remaining 11 species are commonly referred to as river otters, as they predominantly inhabit freshwater ecosystems, including rivers, lakes, and streams.

River otters

River otters, true to their name, are typically found in freshwater habitats. Their sleeping and resting behaviors exhibit distinct patterns. River otters construct burrows near the water's edge but keep them dry for sleeping purposes. These burrows often consist of underground chambers that they construct and furnish with materials like leaves, mosses, hairs, and bark. Most burrows have underwater entrances, enabling otters to swiftly enter and exit, while providing them with a safe retreat.

Sea otters

In coastal marine ecosystems, sea otters exhibit distinct sleeping behaviors compared to their freshwater counterparts. Unlike river otters, sea otters do not rely on dug or underground burrows for sleep. Instead, they inhabit the interface between the sea and rocky coastal areas, which provide them with protective shelters against potential predators. While sea otters primarily reside in marine environments, they also make use of terrestrial spaces for various activities, including resting, sunbathing, playing, and grooming.

Sea otters are highly adapted to an aquatic lifestyle and spend the majority of their time in the water. In fact, it is common to observe sea otters sleeping in the water. They have the ability to rest and sleep while floating on their backs, using their buoyant bodies to effortlessly stay afloat. This sleeping position allows them to relax and recharge while remaining in their natural aquatic habitat. In the following sections, we will delve into the specific methods that otters employ to sleep in water without the risk of drowning.

You might be interested in this other article, where we explain in more detail how many types of otters exist.

How Do Otters Sleep? - Where do otters sleep?

How do otters sleep?

The sleeping habits of river otters in freshwater ecosystems are relatively straightforward and not particularly noteworthy. However, it is in the maritime environments that we find intriguing sleeping behaviors among otters, specifically sea otters (Enhydra lutris).

Sea otters, known for spending a significant amount of time in the water, also sleep in aquatic habitats. It is common to observe sea otters holding hands while sleeping. This unique behavior serves a purpose: it keeps the otters together, preventing them from drifting apart during their slumber. They form chains by holding onto each other's forelimbs, maintaining proximity as they rest. This hand-holding ritual helps foster social bonds and ensures that no individual becomes isolated or separated from the group.

Sea otters, however, have another fascinating sleeping technique. While still floating on their backs, they wrap themselves in masses of algae. This natural "blanket" of algae acts as an anchor, preventing them from drifting away with the currents. The lower parts of their bodies remain above the water surface, while the upper portions may rest on their chests or even cover their eyes. This behavior, combined with the use of algae, enables sea otters to maintain a stable position during sleep, minimizing unnecessary movement.

These unique adaptations highlight the remarkable ways in which otters navigate their sleeping routines in different aquatic habitats.

Be sure to check this other article, where we provide a list of other aquatic mammals.

How Do Otters Sleep? - How do otters sleep?

When do otters sleep?

Otters are generally crepuscular animals, which means they are most active during dawn and dusk. Their sleep patterns vary depending on their species and environmental factors.

River otters, for example, tend to be more active during the day and rest during the night. They may sleep in their burrows or secluded areas during nighttime, reserving the daylight hours for hunting, grooming, and other activities.

Sea otters, on the other hand, do not have a strict sleep schedule and can sleep at any time of the day or night. Sea otters often exhibit more flexibility in their sleep patterns, adjusting to their surroundings and the availability of food.

It's important to note that otters are adaptable animals, and their sleep patterns can also be influenced by factors such as environmental disturbances, predation risk, and the availability of food sources. They are known to be light sleepers and can easily wake up and become alert to potential threats.

Do not miss this other article, where we explain if it is possible to have an otter as a pet.

If you want to read similar articles to How Do Otters Sleep?, we recommend you visit our Facts about the animal kingdom category.


Animal Diversity Web (2020). Available at: https://animaldiversity.org/

IUCN (2022). The IUCN Red List of Threatened Species. Version 2021-3. Available at: https://www.iucnredlist.org

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How Do Otters Sleep?