Ducks are a common sight in ponds, lakes, rivers and other bodies of water. Their iconic quack and waddling walk are instantly recognizable. Ducks have a varied diet consisting of plants, seeds, insects and more. But do ducks eat fish? The answer is yes!

If you’re in a hurry, here’s the quick answer: Ducks are omnivorous and will eat small fish, frogs, aquatic insects and crustaceans.

In this comprehensive guide, we’ll cover everything you need to know about the kinds of fish ducks eat. We’ll discuss what fish are part of a duck’s natural diet, how ducks catch fish, differences between species, whether bread is nutritious for them, and more.

Fish are a Natural Part of a Duck’s Diet

Small Fish

Ducks are omnivorous birds that enjoy eating a variety of small fish as part of their natural diet. Some examples of small fish that ducks readily consume include minnows, goldfish, and juvenile carp. Dabbling ducks like mallards are especially adept at catching small fish near the water’s surface, using their serrated bills and quick reflexes to snatch up unsuspecting prey.

Research shows that small fish provide ducks with important nutrients like protein, healthy fats, vitamins, and minerals. These nutrients help fuel ducks for migration, egg production, and chick rearing. Eating small fish enables ducks to thrive in aquatic environments.

According to wildlife experts, a duck’s bill is sensitive enough to detect the movements of tiny fish in water, assisting them in locating food.

Ducks employ a variety of techniques to catch small fish. They may swim along the surface with their heads immersed, using visual cues to spot fish. Or they may put just their bills into the water to sense for prey. Diving ducks like scaup can dive underwater to pursue fish in deeper areas.

Regardless of technique, ducks are well adapted to accessing small fish for food.

Frogs and Tadpoles

In addition to small fish, frogs and tadpoles are another excellent protein source that many ducks will readily eat. Wood frogs, leopard frogs, bullfrogs, and other local amphibian species often fall victim to a duck’s rapid bill.

Ducks hunt for frogs around pond and lake edges, where frogs congregate to feed and lay eggs.

Tadpoles are small, wiggly morsels that ducks can easily scarf down with their specialized mouths. A single adult frog can contain over 5 grams of protein too, offering ducks a hearty nutrient boost. Frogs that are toxic to many animals, like poison dart frogs, are safely consumed by ducks as well thanks to their innate toxin resistance.

Ducks may also forage amongst frog egg masses, eating the protein-rich eggs. With their excellent eyesight, ducks can readily spot the tell-tale jelly-like globs of frog eggs floating at the water’s surface or attached to vegetation.

For migratory ducks preparing for long journeys, frogs and tadpoles are an abundant resource to take advantage of.

Insects and Crustaceans

From a duck’s perspective, ponds and lakes are like an underwater insect buffet waiting to be tapped into. All manner of worms, larvae, water fleas, snails, shrimp, crayfish, and aquatic insects make up a sizable portion of a duck’s nutrition when available.

These high-protein snacks provide essential amino acids for growth and maintenance.

Ducks employ a variety of foraging strategies to uncover crustaceans and insects in water. Puddle ducks will dabble in shallow zones, straining the muddy bottom for hidden creatures. On land, ducks probe through damp soil and leaf litter seeking earthworms and grubs.

Diving ducks dive deep to scour submerged logs and vegetation for aquatic insects.

With specialized filter-like lamellae in their bills, ducks can filter out tiny morsels like daphnia or scuds from mouthfuls of water. Insects unlucky enough to land on the water’s surface are promptly snatched up by hungry ducks as well.

From ants to damselfly nymphs, ducks consume a diverse array of insects and other invertebrates.

How Ducks Catch and Eat Fish

Surface Feeding

Ducks employ a variety of techniques to catch fish found near the surface of ponds, lakes, rivers and other bodies of water. Some species are able to snatch small fish right from the surface using their bills.

Mallard ducks in particular have been observed skimming for insects, tadpoles and small fish in this manner.

Many ducks will also upend, tipping their tails into the air and submerging their heads underwater to search for food. This allows them to find and catch unaware fish hiding in vegetation near the surface.

According to a 2021 study, diving ducks like lesser scaup can catch 10-30% of their daily food intake while upending to feed.

Diving Underwater

Certain duck species are equipped for true diving to catch fish and other prey. Red-crested pochards, tufted ducks and ruddy ducks are all capable divers that chase and capture fish underwater. These diving ducks use their webbed feet to propel themselves downwards, sometimes reaching depths up to 20 feet to pursue speedy fish.

According to avian researchers, the greater scaup duck is one of the best diving ducks, using its specially adapted claw on its hind toe to grip slick fish. Females need to consume over 60 grams of animal protein each day while breeding, most caught by diving underwater.

Filter Feeding

A specialized feeding behavior called filter feeding allows certain duck species to catch fish without having to dive or surface feed. Dabbling ducks like mallards are equipped with dense rows of thin plates called lamellae on their upper and lower bills that function as filters.

This lets them filter small organisms like zooplankton, insect larvae and very small fish from the water.

American black ducks, gadwall, blue-winged teal and other puddle ducks feed mainly by dabbling and filtering. According to a 2020 Cornell University study on waterfowl feeding habits, these ducks can meet almost all their dietary protein needs through filter feeding on invertebrates, insect larvae and tiny fish during breeding season.

Differences Between Duck Species


Mallards are one of the most common and widespread duck species. They are characterized by their iridescent green heads and bright yellow bills. Male mallards have a distinctive white “necklace” around their neck.

Mallards are dabbling ducks, which means they feed primarily on vegetation, insects, and other small invertebrates by “tipping up” in shallow water rather than diving.

When it comes to their diet, mallards are quite flexible and opportunistic. They will eat a variety of aquatic plants like pondweeds, wild celery, and wild rice. They also snack on seeds, acorns, and grains.

Mallards will also eat aquatic insects and larvae, including midges, dragonflies, caddisflies, and more. Additionally, they will eat small fish, tadpoles, and crustaceans if given the chance.

Here are some key facts about the mallard diet:

  • Omnivorous – they eat both plant and animal matter
  • Forage mainly on aquatic vegetation and small invertebrates
  • Opportunistic feeders – eat whatever is locally abundant
  • Will eat corn, wheat, barley, and bread offered by people
  • May nibble on small fish, frogs, tadpoles if available


Unlike mallards, mergansers specialize in eating fish. There are three main species: the common merganser, the hooded merganser, and the red-breasted merganser. These streamlined diving ducks have narrow, serrated bills that help them grip slippery fish.

Mergansers feast primarily on small fish like minnows, sticklebacks, and perch. They capture fish by diving underwater and swimming along the bottom. Their excellent underwater vision allows them to snatch up unsuspecting prey. A merganser can eat several pounds of fish per day!

In addition to fish, mergansers also eat:

  • Aquatic insects
  • Crustaceans
  • Worms
  • Frog tadpoles
  • Aquatic vegetation

But small fish make up over 90% of their diet. Unlike mallards, mergansers are specialists when it comes to fish-catching and eating. Their specialized serrated bills and diving abilities make them adept aquatic predators.

Muscovy Ducks

Native to Mexico, Central, and South America, Muscovy ducks are a tropical species known for their bare red faces. Wild Muscovies inhabit lakes, streams, and wetlands, feeding on various plants and small animals.

Muscovies are omnivorous, eating a diverse combination of plant and animal material. Their diet includes:

  • Seeds and plant matter
  • Insects
  • Snails
  • Tadpoles
  • Small fish
  • Frogs
  • Mice

Compared to mallards and mergansers, Muscovies consume a higher proportion of animal prey. Up to 20% of their diet can come from insects, snails, fish, amphibians, reptiles, and even small mammals.

Muscovies will also scavenge for food waste near farms and in urban areas. They are robust, adaptable ducks that can exploit many different food sources. Their varied diet is well-suited to tropical environments.

Duck Diet Staples: Not Just Fish


While ducks are popularly known for eating fish and other aquatic creatures, plants actually make up a significant portion of a duck’s diet. Ducks are omnivorous birds that feed on a diverse combination of plant and animal matter.

Here are some of the main plant foods that wild ducks regularly consume:

  • Aquatic plants – Ducks dabble in shallow water to reach leaves, seeds, roots and stems of plants like duckweed, water lilies and pondweeds.
  • Terrestrial plants – During nesting season, ducks feed on grains, berries, seeds and greens from land plants to meet increased energy demands.
  • Agricultural crops – Ducks may graze in agricultural fields, eating fallen grain, rice and seeds from crops like corn, wheat and barley.

Plant foods provide ducks with essential carbohydrates and nutrients. Dabbling ducks in particular are well-adapted to utilize aquatic vegetation. Their wide, flat bills allow them to sieve through muddy shorelines filtering out plant material.

Aquatic plants can meet up to 95% of a dabbling duck’s food requirements during non-breeding seasons.


Grains provide an excellent source of energy and nutrients for ducks. During fall and winter, ducks gorge on abundant waste grain in harvested fields. According to a Ducks Unlimited report, cereal grains may comprise over 70% of dabbling ducks’ diets during winter.

Here are some key grains ducks feed on:

  • Corn – One of the most important duck foods, corn provides protein and carbohydrates.
  • Rice – An excellent source of energy, rice grains are consumed by ducks in flooded agricultural fields.
  • Wheat – Waste wheat grains left after harvesting are relished by ducks for their abundant nutrients.
  • Millet – The small seeds of millet grasses are eagerly eaten by wild ducks.

Interestingly, female ducks purposefully lead their ducklings to fields with nutritious waste grain in early spring. This helps ducklings get a vital source of food when their protein requirements are highest during growth.

These grain feeding grounds are critical for duckling survival and development.

Insects and Worms

In addition to plants and grains, ducks seek out protein-rich insects and worms. Aquatic invertebrates eaten by ducks include:

  • Dragonfly larvae
  • Damselfly nymphs
  • Caddisfly larvae
  • Mayfly nymphs
  • Mosquito larvae
  • Freshwater shrimp
  • Snails
  • Aquatic worms

On land, ducks probe through soil and mud to catch earthworms, beetles, flies, ants, grasshoppers, crickets and other insects. Ducks of all ages eat insects, which provide essential amino acids and fatty acids.

However, insect consumption increases for females prior to egg-laying as they have higher protein requirements. Ducks also feed more insects to newly hatched ducklings, which need the protein boost to grow and develop.

Should You Feed Ducks Bread?

Downsides of Bread

Bread has long been a popular food item that many people use to feed ducks. However, in recent years, experts have advised against doing so for several important reasons:

  • Nutritional deficiency – Bread lacks the vitamins and minerals ducks need in their diet. Feeding bread can lead to malnutrition.
  • Poor digestion – Ducks have difficulty digesting bread properly. The yeast and carbohydrates in bread can ferment in their digestive system and cause health issues.
  • Angel wing – Too much bread can lead to a deformity called “angel wing,” where a duck’s wings twist out at an odd angle and render the duck unable to fly.
  • Pollution – Uneaten bread that accumulates in water can lead to increased bacteria and algae, reducing water quality.
  • Dependency – Ducks can become too reliant on humans for an unhealthy food source and stop foraging naturally for more nutritious foods.

One study conducted by researchers at the University of Exeter found that ducks and swans fed a diet of approximately 50% bread showed signs of malnutrition and poor growth compared to those fed a more natural diet.

Healthier Alternatives

While bread is cheap and convenient for us, there are much healthier foods you can feed ducks instead:

  • Seeds and grains – These provide protein and carbs, like birdseed, cracked corn, wheat, barley, oats, and rice.
  • Vegetables – Fresh greens like lettuce, kale, spinach provide vitamins and minerals.
  • Fruit – Chopped grapes, berries, and melons for fiber and nutrients.
  • Mealworms – An excellent source of protein to promote growth.

You can find special “duck feed” at many pet stores that contain a blend of seeds, grains, dried insects and vitamin supplements specifically formulated for ducks.

Spreading out feed over a wide area can also prevent ducks from crowding and fighting over food. And be sure to follow any local guidelines on where and how much you can feed ducks in public spaces.

While our hearts are in the right place wanting to feed cute ducks, we truly do more harm than good giving them inappropriate foods like bread. With a little care and research into their dietary needs, we can still enjoy feeding ducks healthy, natural foods that nourish them.


In conclusion, many species of ducks regularly eat small fish as part of their omnivorous diet. They are well-adapted to catch freshwater fish and other aquatic creatures. While fish form a healthy part of a duck’s natural diet, there are also many other foods ducks need to stay nourished such as plants, grains and insects.

Understanding what ducks eat helps bird enthusiasts better connect with these fun waterfowl. Next time you see ducks in a pond, take a closer look at their feeding behavior and you might just spot them snacking on small fish!

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