Ducks putting their heads underwater is a common sight in ponds and lakes. If you’ve ever wondered why ducks dip their heads underwater, you’re not alone. As harmless as ducks may seem, there are actually some fascinating reasons behind this duck behavior.

If you’re short on time, here’s a quick answer to your question: Ducks put their heads underwater to look for food, clean themselves, evade predators, and more.

In this comprehensive article, we’ll explore the top reasons ducks immerse their heads in water and provide plenty of duck facts to satisfy your curiosity.

Searching for Food

Dabbling for Aquatic Plants

One of the main reasons ducks frequently dip their heads underwater is to search for aquatic plants to eat. Species like mallards are dabbling ducks, meaning they tip tail-up and only submerge their heads and necks rather than diving fully below the surface.

They use their broad bills underwater to dabble through mud and vegetation looking for tasty shoots, leaves, roots, and seeds.

Favored snacks for dabbling ducks include algae, water lilies, pondweeds, wild celery, and wild rice. A key reason ducks evolved long, flexible necks was for easily plunging their heads underwater to grab mouthfuls of plants while keeping most of their bodies above the surface.

Their serrated bill edges also help grip slippery greens. By vigorously paddling their feet, dabbling duck species can remain in place while gorging on underwater vegetation through repetitive head-dipping.

Snatching Up Aquatic Invertebrates

Along with plants, ducks also search for animal protein underwater in the form of aquatic invertebrates. Insect larva, snails, shrimp, tadpoles, small fish, and more make up a sizable chunk of many ducks’ diets.

Their specialized bills have nerve endings allowing them to detect the movements of hiding prey. Underwater dabbling serves the purpose of churning up mud that exposes benthic creatures for hungry ducks to gobble up.

Diving duck species are the most voracious underwater insectivores. They propel their entire bodies below the surface to forage along muddy bottoms for unsuspecting invertebrates. A typical diving duration ranges 15-30 seconds depending on factors like depth and temperature.

Thanks to high myoglobin content in their wing muscles, diving ducks can efficiently store oxygen for submarine trips of over a minute to hunt down food. Their superb underwater vision and flexible neck allow for spying camouflaged critters.

Atlantic brant geese 44 grams aquatic plants
Ring-necked ducks 80% aquatic invertebrates

As illustrated above, the nutritional makeup differs amongst waterfowl species. Still, all ducks get a tremendous foraging boost from their specialized bill and neck allowing them to snatch up a diverse buffet below the waterline. For more info, check out sites like Ducks Unlimited.

Grooming and Preening

Ducks spend a significant amount of time grooming and preening their feathers to keep them in top condition. This serves several important purposes for ducks:


A duck’s feathers are naturally waterproof due to an oil called preen oil that is secreted from a gland near the base of their tail. When a duck preens, it spreads this oil over its feathers to maintain their water-repellent properties.

This helps insulate the duck and prevent water from penetrating to their skin.


Preening helps ducks clean their feathers and keep them free of parasites, dirt and other debris. As they preen, ducks use their bill to distribute the preen oil and straighten out feathers. This keeps their plumage neat, clean and healthy.


Well-groomed feathers are essential for a duck’s health and comfort. Straight, clean and waterproofed feathers provide better insulation and buoyancy in the water. Proper preening also removes dead feathers and helps check for any parasites or skin irritation.

Ducks that don’t preen adequately can lose their waterproofing and insulating abilities.

Social Bonding

In duck flocks, preening often occurs in groups with ducks nibbling through each other’s plumage social. This helps strengthen social bonds within duck communities.

Ducks will spend time preening both in the water and on land. When on land, you’ll see ducks rubbing their head over their back to reach all their feathers. They’ll also submerge their head in water and preen with their bill to distribute the preen oil.

This serves the dual purpose of waterproofing and cooling themselves at the same time.

Evading Predators

Hiding from Birds of Prey

Ducks have developed several clever strategies to avoid predation from birds of prey like eagles, hawks, and falcons. One key tactic is hiding underwater where birds can’t see or reach them. When ducks sense danger overhead, they will quickly submerge their bodies and only leave their heads above the surface.

This allows them to monitor the threat while remaining mostly hidden. Ducks can also dive deep underwater and swim away to escape aerial predators. Their streamlined bodies and webbed feet make them agile swimmers able to outmaneuver hunting birds.

Ducks may also hide among reeds and vegetation at the water’s edge. Their drab brown plumage provides camouflage against the shoreline. Sitting still amongst the reeds, a duck is very difficult for birds to spot from the air.

Ducks especially use this tactic when leading their ducklings, hiding the young ones in the reeds while adults keep watch for predators. Group vigilance is another key strategy. With so many eyes scanning the skies, ducks can quickly alert each other to looming threats and take appropriate evasive action.

Avoiding Land Predators

On land, ducks face predation from foxes, coyotes, bobcats, and other mammals. Here, hiding underwater is not an option, so ducks have evolved other clever survival techniques. One strategy is to nest in difficult to reach locations.

Ducks often build nests on small islands or elevated platforms far from shore. This isolates them from land predators. Clifftop nests are also popular as they deny predators access.

Ducks may also locate their nests near wasp or bee colonies. The presence of stinging insects helps deter mammals from approaching the eggs. If confronted by a predator on land, a duck will first hiss aggressively and spread its wings to appear larger and intimidating.

If this bluffing fails to scare off the predator, the duck will bite viciously at the predator’s face and eyes while beating it with its wings. This furious display often confuses predators long enough for the duck to escape back to the safety of the water.


Ducks have a fascinating ability to regulate their body temperature through various behavioral adaptations. When they put their heads underwater, it serves an important thermoregulatory function.

Ducks do not have sweat glands like humans do. Instead, they rely on their respiratory system and circulatory system to release excess heat and cool their bodies down. By submerging their heads in water, ducks are able to cool the blood vessels in their head and neck.

The cooled blood then circulates through the rest of their body, bringing their core temperature down. This allows ducks to maintain a healthy body temperature even when air temperatures rise. Some key ways ducks use water to thermoregulate include:

  • Evaporative cooling – When a duck’s head and neck get wet, the water evaporates off their feathers and skin, pulling heat away from their bodies.
  • Conductive cooling – Water conducts heat away from the body more effectively than air. Submerging in water allows heat to dissipate more rapidly.
  • Vasodilation – Blood vessels in a duck’s head and neck dilate to increase blood flow to the skin surface when underwater. This dumps excess core heat into the water.

Interestingly, ducks have a countercurrent heat exchange system in their legs and feet that minimizes heat loss when standing in cold water. Arteries carrying warm blood from the duck’s core run close to veins carrying cooler blood from the feet.

This allows heat to conduct from the arteries into the veins, keeping the feet from getting too cold. This same system helps keep a duck’s core warm when swimming in frigid waters.

Being able to carefully control body temperature through aquatic head wetting and other mechanisms is extremely important for duck survival. It allows ducks to remain active while expending energy during flight, migration, and other behaviors.

Proper thermoregulation also enables ducks to thrive in diverse environments from the Arctic to the tropics. By immersing their heads in water, ducks can rapidly cool down when their bodies overheat. This clever trick is one of the secrets behind ducks’ amazing ability to live in so many habitats around the world.

Resting and Sleeping

Ducks spend a good portion of their day resting and sleeping. Here are some key facts about how ducks rest and sleep:

How Ducks Rest

Ducks alternate periods of activity with periods of rest throughout the day. They will often rest in groups, sitting or standing together near the water’s edge. During rest periods, ducks will:

  • Sit or stand still, sometimes tucking one leg up into their feathers
  • Preen themselves, using their beak and tongue to clean and align their feathers
  • Dozed lightly, keeping their eyes partly open to stay alert to danger

Rest periods allow ducks to conserve energy between feeding or swimming sessions. Ducks may spend more time resting on cold days when they need to conserve body heat. Mother ducks with ducklings will also rest more to allow the ducklings time to sleep.

How Ducks Sleep

At night, ducks will settle in to sleep for longer periods of 6-8 hours. Ducks generally sleep at the water’s edge or on the water itself:

  • Groups of ducks will gather in sheltered spots along the shoreline to sleep at night
  • Some ducks like mallards may sleep floating in the water, either individually or in groups
  • Ducks keep one eye open when sleeping in the water to watch for predators
  • Ducks also sometimes sleep while standing on one leg on land, again keeping one eye open for threats

Why do ducks sleep at the water’s edge? Being near the water allows ducks to escape quickly if threatened on land during the night. Sleeping on the water also allows ducks to hide from predators better than on land.

Ducks Total Sleep (per day)
Mallards 6-8 hours
Wood ducks About 8 hours
Muscovy ducks 4-6 hours

Different duck species have varying total sleep requirements per day. For example, mallards sleep 6-8 hours, while muscovy ducks sleep only 4-6 hours (source).

Why Ducks Put Their Heads Underwater to Rest

You may see ducks resting with their heads tucked under their wings or submerged underwater. Here’s why they do this:

  • Tucking the head under the wing allows ducks to block out light and disturbances to nap
  • Submerging the head underwater likely helps ducks rest their neck muscles after hours spent swimming and feeding
  • Putting their head underwater also lets ducks keep a lookout for underwater predators

So next time you see a duck resting or sleeping with its head underwater, know that this serves several important purposes for the duck! Overall, understanding how ducks rest and sleep provides insight into their daily rhythms and behaviors.


As you can see, ducks have plenty of great reasons to dip their heads underwater. From foraging for food to taking refuge from predators, this behavior is essential to a duck’s survival. Dabbling ducks in particular have evolved specialized bills and foraging methods to take advantage of their watery habitats.

The next time you see a duck bobbing for its next meal or hiding from a threat, take a moment to appreciate the ingenious ways these waterfowl have adapted to aquatic living. After reading this, we hope you have a new appreciation for ducks and why they put their heads underwater.

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