What Do Rainbow Trout Eat?

What do rainbow trout eat in their day-to-day lives? Rainbow trout have a varied diet consisting of everything from insects like nymphs, beetles and grasshoppers to fish eggs, leeches, mollusks, crustaceans and even larger prey like mice and other fish.

While rainbow trout are surprisingly selective eaters during different seasons and at certain periods of the day, they also tend to be very opportunistic and will gorge themselves when the getting is good.

Don’t miss our Guide to Productive Rainbow Trout Patterns.

What Do Rainbow Trout Eat?

Rainbow trout are both selective and aggressive eaters. Their diet consists of many different species, and their main choices are scuds, shrimp, mussels, leeches, mayflies, nymphs and fish. We’ll get into more detailed varieties of each below.

Rainbow Trout Eat Crustaceans

Rainbow trout will eat multiple different crustaceans throughout their lives. While certain crustaceans are specific to certain areas, freshwater shrimp, crayfish, scuds and sowbugs live in almost all trout water throughout the world.

Shrimp

Freshwater shrimp are a staple for feeding rainbow trout. Shrimp make their homes in the cold, oxygenated lakes and streams that are often home to rainbow trout. As a result, they’re frequently targeted during feeding bursts.

Tying on a freshwater shrimp pattern is a great option for luring a feeding rainbow.

Crayfish

Crayfish are another member of the crustacean family that rainbow trout love.

A stripped crawfish pattern along a rocky bank, in either a lake or a stream, can entice even the laziest of rainbow trout.

 

Scuds

Scuds are one of the most popular food sources for rainbow trout (as well as other trout species). In specific areas around the world, scuds can make up over half of a rainbow trout’s daily diet.

Drifting scuds along a cut bank or through a deep pool is a great option for catching rainbows.

Sowbugs

Similar to scuds, sowbugs are a prevalent food source for rainbow trout, specifically younger ones.

Sowbugs live most of their lives on land, but will frequently fall or be swept into the water where stalking rainbows are ready to strike.

 

Rainbow Trout Eat Mammals

Rainbow trout won’t shy away from eating larger animals if given the chance. Rainbow trout are aggressive feeders and will eat turtles, tortoises and even mice if the opportunity presents itself.

Mouse

Mice are one of the mammals that a rainbow trout will eat if given the chance.

One of the most enjoyable ways to catch a rainbow is to float a mouse pattern along a deep bank once the sun goes down.

Tortoise

Rainbow trout will also take advantage of an exposed turtle/tortoise.

Turtles frequent many of the lakes and streams rainbow trout call home, and drifting a turtle fly can induce an aggressive strike.

Rainbow Trout Eat Amphibians

Amphibians are another common food source for rainbow trout. Frogs, salamanders and tadpoles will entice feeding rainbows due mainly to their quick movements and the amount of substance they provide.

Frog

Rainbow trout will eat frogs whenever they’re available. The quick movement of their swimming motion is often too much to take for an idling rainbow.

Quickly and sporadically stripping a frog across a lake or stream will oftentimes garner a rainbow’s attention.

Salamander

Rainbow trout will also eat salamanders. Though not as prevalent throughout the world as other amphibians, salamanders are still a top choice for feeding rainbows.

Before you tie on your salamander fly, research which types are prevalent in your area.

Rainbow Trout Eat Mollusks

There are a variety of mollusks that reside in trout habitat and rainbow trout eat almost all of them. In the simplest of terms, mollusks are invertebrates that have a hard outer shell used for protection.

The most common ones that appear in a rainbow trout’s diet are snails and mussels.

Snail

Snails are the most common mollusk and as a result are a very popular food option for rainbow trout.

Slowly drifting a snail fly through deeper parts of a small stream or along the edge of a lake is a great option for when the bite stagnates.

Mussels

Mussels are also an extremely prevalent food source in most streams, lakes and rivers.

This makes them an easy target for loafing rainbows. Often caught up by the current or stuck on rocks, they become a simple meal for a waiting trout.

Rainbow Trout Eat Worms

Worms are a primary target for rainbow trout. There are multiple different types of worms that reside near and in trout waters throughout the world, and the two most prevalent ones are earthworms and leeches.

Earthworm

Rainbow trout will eat earthworms anytime they’re available. Earthworms are one of the larger worm species and as such provide trout with a very substantial meal.

Fishing with a worm by floating an earthworm along a cut bank or through a deep pool is a great option for catching a rainbow.

Leech

Rainbow trout love to eat leeches. Found in many streams, rivers, and lakes, leeches are a staple of rainbow trout’s diet whenever they’re available.

Smoothly stripping a leech to mimic their “S” shaped swimming motion will frequently draw a rainbow’s attention.

Rainbow Trout Eat Smaller Fish

Smaller fish are oftentimes the top food choice for a mature rainbow trout. Rainbow trout are aggressive feeders and as soon as they reach over one foot in length, they turn their attention to other fish and minnows.

Same Species Minnows

Rainbow trout will seek out minnows as a main food source and won’t shy away from other rainbow trout minnows as well.

As rainbow trout grow and mature, they’ll even start feeding on larger rainbows.

Other Minnows

Found in almost every lake, stream or river, minnows are at the top of a rainbow trout’s diet.

They’re not picky about the type and will eat brown, brook, rainbow, cutthroat and multiple other types of minnows when they’re present.

Quickly stripping a minnow along the bank or across the current can induce a strike.

Sculpin

Sculpin are another member of the minnow family that’s very common in trout habitats.

Sculpin, also known as bullhead, provide rainbow trout with another substantial food option when other minnows aren’t present.

Rainbow Trout Eat Fish Eggs

During spawning season, trout eggs are added to a rainbow trout’s diet. In the months of October to November, trout and other fish spawn and oftentimes eggs will be swept away by the current right past feeding rainbows.

Salmon Egg

Rainbow trout are frequently found in similar habitats as salmon, especially during the spawn.

As a result, salmon eggs become a common meal source throughout the fall months.

Other Rainbow Trout Eggs

Just like brown trout and brook trout, rainbow trout also spawn in the fall. With such commotion in many streams during that time period, eggs are caught in the current and brought downstream. Rainbow trout will eat all types of eggs and won’t shy away from rainbow trout eggs either.

Rainbow Trout Eat Terrestrials

Like eggs in the fall, terrestrials are added to the rainbow trout diet for the summer. As the weather warms, grasshoppers, beetles, ants, mayflies, caddisflies, moths, midges, and stoneflies become active and prevalent.

Grasshoppers

Grasshoppers are one of the main terrestrial choices for a feeding rainbow. Grasshoppers live in the grasslands surrounding lakes and streams and will oftentimes be blown or fall into the water where feeding rainbows are waiting.

Floating a grasshopper along a grassy bank can lead to aggressive strikes.

Beetles

Beetles are another common terrestrial that resides near bodies of water that trout call home. When a beetle falls into the water, rainbow trout won’t hesitate.

Drifting a beetle through the current on a summer day can lead to surprising results.

Ants

Ants may be the most common terrestrial.

Usually coming out from hibernation earlier than others, ants will be swept or blown off rocks where rainbow trout will be waiting.

Throwing an ant like Chernobyl ant pattern in the early parts of the summer is a great way to catch a lurking rainbow.

Mayflies

Mayflies are another extremely common terrestrial.

Often hatching in the morning and evenings, mayflies will sit on top of the water getting their wings ready to fly away. That gives rainbow trout plenty of opportunity for an easy meal.

Caddisflies

Caddisflies reside in almost all the same areas as mayflies do, and as a result are a frequent snack for a rising rainbow trout.

There are thousands of species of caddisflies and rainbow trout will eat them directly off the surface during intense hatches.

The Elk Hair Caddis pattern is a dry fly that’s one of the best caddisflies to imitate to catch more fish.

Moths

Moths are another popular and prevalent food item for rainbow trout. Mostly active at night, moths will be blown in or swept up in the current and become an easy meal.

Floating a moth out as the sun is setting is a great way to land a feeding rainbow.

Midges

Rainbow trout eat midges frequently throughout the year.

The two of the most common midges in a rainbow trout’s diet are mosquitos and gnats.

Cicadas

Cicadas are one of the larger terrestrials in a rainbow trout’s diet. Common in mid to late summer, cicadas become a frequent meal for rising rainbows.

Throwing a cicada along a cut bank is a great way to encourage a strike.

Dragonflies

Dragonflies are another summer meal source for rainbow trout.

Dragonflies spend most of their time flying above the water eating midges. It’s not uncommon to see a rainbow trout launch out of the water to grab a feeding dragonfly.

Stoneflies

Living in most trout waters throughout North America, both stonefly midges as well as the winged adults are frequently eaten by rainbow trout.

Rainbow Trout Eat Nymphs

Nymphs are a staple of a trout’s diet, and rainbow trout are no exception. Nymphs (insects that are not fully developed) live in trout waters all throughout the world and can be found year round, making them a crucial part of a rainbow trout’s diet.

Caddis Nymph

Caddis nymphs are caddisflies that haven’t fully matured. They’re found in trout habitat all around the world and are sipped up by rainbows as the current brings them by.

Drifting them through deep pools any time of year will often produce results.

Midge

Most midges come in a gnat or mosquito form, but there are many different types.

They’re extremely small insects, but rainbow trout will eat them consistently throughout the day.

Mayfly Nymph

Mayfly nymphs are another prevalent nymph in stream, lake and river ecosystems.

Mayfly nymphs spend most of their time deep in the water column, and rainbow trout will sip them up as the current carries them past.

Stonefly Nymph

Stonefly nymphs are one of the larger nymphs in the ecosystem and as a result are a more substantial snack for rainbow trout.

Stonefly nymphs can only survive in cold, oxygenated waters, so they’re found in higher elevation lakes and streams.

Dragonfly Nymph

Dragonfly nymphs are another one of the larger nymphs in a rainbow trout’s diet.

They spend most of their lives on the bottom of a lake or a stream, so floating a dragonfly nymph in the deeper parts of a stream or river is a great option when the bite slows down.

You can check the absolute best methods to learn about fly fishing nymphs.

Rainbow Trout Eat Moss & Algae

Rainbow trout, while being aggressive feeders, also aren’t ones to shy away from an easy meal. Moss and algae are common in many rivers and streams that trout call home. While they may not be the first choice, rainbows will partake if other options are less prevalent.

Moss and algae will also occasionally be caught in the current. Out of a quick reaction, a rainbow trout may grab it as it floats by.

Rainbow Trout Eat Stones & Rocks

Why do rainbow trout eat stones and rocks? Rainbow trout won’t eat stones and rocks on purpose, but when they’re eating nymphs or other emergers off the bottom, stones and rocks will occasionally be picked up with them.

Rainbow Trout Have a Seasonal Diet

Rainbow trout, like most fish, have a diet that varies based on the season. At certain times of the year, different species aren’t available due to weather and temperature, and a trout’s diet will shift towards more prevalent options.

What Do Rainbow Trout Eat in Winter?

Throughout the winter, a rainbow trout’s diet is mostly made up of minnows, nymphs and midges. In cold temperatures, a rainbow trout’s metabolism will slow slightly and thus their need for large amounts of food will diminish.

What Do Rainbow Trout Eat in Early Spring?

In early spring, a rainbow trout’s eating habits can change depending on the day. On warmer days, rainbow trout will be more active and chase minnows, shrimp, and caddisflies. However, on cold, dark days, they’ll go back to their winter feeding habits.

What Do Rainbow Trout Eat in Summer?

Summer is the primary feeding season for rainbow trout. Their diets become quite varied based on how many options are present June-August. Their main prey is normally fish, minnows and amphibians, but they’ll also feed on stone and salmon flies, nymphs, caddisflies, mayflies and a variety of other insects and terrestrials.

What Do Rainbow Trout Eat in Early Fall?

Early fall is also an active feeding season for rainbow trout. As they begin stocking up for the trip to their spawning grounds, they’ll eat everything from midges and nymphs to minnows, other trout, earthworms and leeches.

What Do Rainbow Trout Eat in the Fall?

During the fall, rainbow trout will eat multiple different species. As it gets colder, some options will diminish, but they’ll still eat minnows, sculpin, midges, nymphs, moths and a variety of insects. Fish eggs will also be added to the diet in later fall post spawn.

When Do Rainbow Trout Feed?

Rainbow trout, like most other trout, will eat all throughout the day and night. Weather and season can affect that, but rainbow trout will take advantage of an easy meal at any time of day.

What Do Rainbow Trout Eat at Dawn?

Rainbow trout are most active at dusk and dawn and will feed on a variety of species. The lack of light and large shadows allow rainbows to sneak up on unsuspecting crayfish, minnows, frogs, and other trout.

What Do Rainbow Trout Eat Midday?

Depending on the season, rainbow trout can be less active at midday than other times of the day. Oftentimes they will sit in deeper pools that provide protection and eat smaller nymphs and minnows that pass by.

What Do Rainbow Trout Eat at Sunset?

At sunset, you’ll find rainbow trout eating a variety of different food items. May and caddisflies are often hatching as well as nymphs making their way through the water column. The lack of direct sunlight also provides cover for rainbows to hunt for other trout, minnows and amphibians.

What Do Rainbow Trout Eat at Dusk?

Dusk is another active feeding time for rainbow trout. As it gets darker, their main choices are minnows, sculpin, moths, midges and hatching emergers.

What Do Rainbow Trout Eat at Night?

Rainbow trout will continue to eat at night, though not as frequently as during the day. However, earthworms and mice are most active at night, and when an opportunity for either of those presents itself, rainbows will pounce.

A Rainbow Trout’s Diet Changes With Its Environment

A rainbow trout’s diet is dependent on multiple factors, but the one with the biggest influence is the environment. Rainbow trout live in ponds, rivers, lakes and streams, and depending on size, temperature and location their diets will vary greatly.

What Do Rainbow Trout Eat in Lakes?

In lakes, rainbow trout will eat minnows, frogs, sculpins, turtles as well as other trout. They’ll also eat a myriad of insects, amphibians, and crustaceans.

What Do Rainbow Trout Eat in Rivers?

Rivers contain an immense amount of species that appear on a rainbow trout’s food list. In terms of larger options, the most common are earthworms, leeches and minnows. However, there are also hundreds of smaller options as well, from salmon and stoneflies to midges, shrimp, grasshoppers, beetles and dragonflies.

What Do Rainbow Trout Eat in Ponds?

Rainbow trout living in ponds will feed on amphibians like frogs and salamanders as well as crayfish, minnows, sculpin, sowbugs and other crustaceans.

What Do Rainbow Trout Eat in Small Creeks?

Rainbow trout living in small creeks will eat a wide variety of food. Mayflies, caddisflies, beetles, ants, dragonflies, minnows, sculpins, frogs, midges and crustaceans are all common food choices for rainbows living in small creeks.

In Conclusion

Rainbow trout are aggressive feeders and have a varied diet. As rainbow trout grow, they begin to focus on larger options like minnows, sculpins, and other trout. They’ll continually feed on midges, nymphs, caddis and mayflies throughout their lives, but as they age, larger prey becomes the top choice.

Environment, time of day and season of the year have a large effect on what rainbows are eating. Knowing the top choices that rainbows will eat at any time of year will give you the highest chance of success.

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