The flathead catfish is big and strong. It’s also known as the yellow cat, mud cat, and shovelhead cat. It can grow up to 4 feet long and weigh over 100 pounds. The biggest one caught was 123 pounds, caught in Kansas in 1998.
So, what do flathead catfish eat? They are hunters, not scavengers. They have a special head for catching prey. They hide in deep water during the day and hunt at night.
Young flathead catfish eat worms and small insects. As they grow, they start to eat fish like sunfish and carp. They eat a variety of fish, including other catfish.
Knowing what flathead catfish eat helps anglers and managers. They hunt at night and like to hide. This is why they are so good at catching food.
Flathead catfish diet at a glance: live prey over scavenging
Flatheads love to eat live forage catfish. They use their senses to catch prey. Their wide mouth lets them eat big meals quickly.
Predatory, not scavengers: why flatheads target live forage
Flatheads are predatory catfish. They hide and jump out to catch fish. They prefer live fish over dead ones.
From insects to fish: how the menu shifts with size
Young flatheads eat insects and worms. As they grow, they start to eat crayfish. Then, they switch to fish.
Common prey species in U.S. waters
Flatheads eat what they can catch. They like sunfish, shad, and carp. They also eat bullheads and other catfish.
- Sunfish such as green sunfish Lepomis cyanellus
- Shad, including gizzard shad Dorosoma cepedianum
- Carp, suckers, and freshwater drum Aplodinotus grunniens
- Bullheads, channel catfish Ictalurus punctatus, and other flatheads
They also eat crayfish, birds, and turtles. But live fish are their main food. This shows they are live forage catfish experts.
Juvenile feeding habits: insects, worms, and crustaceans
Right after hatching, young flatheads eat easy food near cover. They swim in shallow areas, eating worms, tiny crustaceans, and soft prey at night. This diet helps them grow in the first warm months.
Early life stages: annelid worms, insect larvae, and tiny crustaceans
When fish are about 0.4 inches, they start eating. They eat insect larvae, like mayflies and midges, and small crustaceans. They also eat worms in some places.
This diet keeps them safe and growing fast in calm water. For more on young catfish eating crustaceans, see this guide to what catfish eat.
The 4-inch threshold: adding crayfish and small fish
When they grow to 4 inches, young catfish hunt alone. They start eating crayfish and small fish. This helps them grow to 4–6 inches in a year, and up to 8 inches in the South.
Even when they’re bigger, they keep eating soft invertebrates. Their diet changes as they get stronger, eating bigger crustaceans.
How temperature boosts juvenile appetite around 66–90°F
When water gets to about 66°F, young catfish eat more. Their appetite stays high until it cools down. Below 60°F, they eat less. Near 52°F, they stop eating until it warms up again.
This pattern makes them hunt at night in shallow areas. Warmer water means more food and faster growth. They start eating crayfish and fish instead of worms and larvae.
| Prey Type | When It Peaks | Size Range Most Common | Notes |
|---|---|---|---|
| Annelid worms | Fry to early juvenile | 0.4–3 inches | Easy to swallow; abundant in soft substrates after rains. |
| Insect larvae | Fry through first summer | 0.4–4 inches | Core energy source; drift at dusk favors quick strikes. |
| Tiny crustaceans | Fry to mid-juvenile | 0.4–4 inches | Amphipods and copepods pack protein; dense in vegetation. |
| Crayfish | Post 4-inch shift | 4–8 inches | Marks the crayfish transition; shell handling improves with size. |
| Small fish | Post 4-inch shift | 4–8 inches | Minnows and young sunfish taken around cover in low light. |
| Temperature effect | 66–90°F strongest | All juvenile sizes | Feeding surges with warmth; slows near 60°F and stalls below ~52°F. |
Adult menu: mostly fish, with opportunistic surprises
When a flathead grows over 10 inches, it starts to eat mostly fish. It uses stealth and power to hunt. This changes how and where it finds food.
Primary forage: sunfish, shad, carp, suckers, bullheads, and other catfish
The main foods are sunfish, shad, and carp. Gizzard shad, common carp, and bluegill are favorites. Suckers, bullheads, and other catfish also make the list.
Its wide mouth lets it eat big fish. It ambushes them in deep holes and near wood.
At night, it moves to shallower waters. This is when fish are most active.
Opportunism in action: birds, crabs, and turtles when available
Flatheads don’t miss out on easy food. In rivers, they eat crabs. They also catch small birds and turtles.
They look for food in areas with lots of movement. This includes current seams and flooded brush.
Nocturnal ambush tactics and large mouth gape advantages
Flatheads are active at night. They hide in the day and ambush at night. Many fish are caught from below.
They also lie on the bottom, waiting for food. Their wide mouth helps them catch big prey. This is why they are successful at night.
What does flathead catfish eat
Diet changes with size and season. This is true for rivers and reservoirs in the United States. Biologists say there’s a clear pattern in what flatheads eat based on their size, where they live, and what’s available to eat.
Under 10 inches: invertebrates dominate
For under 10 inch flathead food, think small and soft. They eat tiny fish, insect larvae, worms, and small crustaceans. When they grow to four inches, crayfish become part of their diet, found in woody areas and near rocks.
This is the start of the piscivory threshold catfish story. As they grow, they need more energy. But their small mouths mean they mostly eat invertebrates for calories.
10 inches and larger: fish make up nearly all calories
At about 10 inches, the piscivory threshold catfish really starts. Flatheads mainly eat fish after this. They go for shad, sunfish, carp, suckers, bullheads, and other catfish. These fish are big and easy to catch, giving flatheads lots of energy.
This change makes the flathead size-based diet clear. Big prey fits their wide mouths and ambush style. This means they can rest for a long time before hunting again.
Seasonal shifts in fish prey for older flatheads
Older flatheads follow the fish they eat. In summer, they eat gizzard shad and bluegill near fast water. In fall, they go deeper for suckers and carp.
These seasonal prey shifts catfish change with the weather, water flow, and daylight. They mostly eat fish, but the type of fish changes with the season and what’s available.
When and where flatheads feed: habitat and timing matter
Flatheads like to hide in tight spots. They stay in the same area, up to two kilometers, all year. They go back to the same places over and over.
Day vs. night: daytime cover, nighttime foraging in the shallows
During the day, they hide in dark places. At night, they move to shallower areas to hunt. They hunt best after midnight and in the early morning when it’s dark.
Preferred habitats: deep pools, slow currents, woody debris, undercut banks
They like deep pools with lots of wood. Places like undercut banks and logjams are perfect for them. These spots make it easy for them to ambush prey.
Diel movement peaks in summer; winter slow-down
In summer, they move more at night. This happens from June to August. But in fall, they move less. Below 60°F, they move even less. Near 52°F, they almost stop moving until it gets warmer again.
How growth and age change the diet
Flathead catfish don’t eat the same way forever. They start small and grow bigger, changing what they eat. Fry and tiny juveniles eat insect larvae, worms, and tiny crustaceans in calm water.
As they grow, they can eat more. They start to eat crayfish and small fish when they get stronger. This is when they start to eat more fish.
By four inches, they can eat bigger things. They have stronger jaws and swim faster. This lets them catch crayfish and small fish.
By ten inches, they mostly eat fish. This is because fish give them more energy. They eat fish like shad and sunfish.
As they grow, they eat different things. They eat more fish and less crayfish. This is because they can swim faster and catch more fish.
They also eat in different places. They swim deeper in the day and near the edges at night. This helps them catch fish like shad and sunfish.
By age two, crayfish are less important. By age six, fish are the main food. This is because they can swim faster and catch more fish.
Flatheads grow about three inches a year after the first year. Males get ready to breed at about twelve inches. Females are ready at about sixteen to eighteen inches.
| Life Stage / Size | Primary Prey | Key Drivers | Feeding Notes |
|---|---|---|---|
| Fry to Small Juveniles | Insect larvae, annelid worms, tiny crustaceans | Low speed, strong catfish gape limitation, shallow cover | Short chases; picks soft-bodied prey in slack water |
| ~4 Inches | Crayfish, small fish (minnows, young sunfish) | Wider gape, improved burst speed, better handling | Begins the ontogenetic diet shift catfish trajectory |
| ~10 Inches | Fish dominate; crayfish drop | Age-related piscivory, stronger suction, larger home range | Targets energy-rich schools like shad and juvenile carp |
| Adults | Sunfish, shad, carp, suckers, bullheads | Minimal catfish gape limitation, nocturnal ambush | Seasonal prey switching tracks availability and flow |
In rivers like the Mississippi and reservoirs from Texas to Pennsylvania, the pattern is the same. The diet starts with small things and ends with big fish. By the time they are adults, they mostly eat fish. Rarely, they might eat something too big for their mouth.
Crayfish in the diet: big early, phased out by about age six
Young flatheads love to eat crayfish. By age two, many have crayfish shells in their stomachs. But as they grow, they eat less crayfish.
As they get bigger, they can eat bigger prey. This change happens fast, between ages four and six. Anglers notice this too, seeing more fish caught than crayfish.
Why crayfish fade from the menu in mature fish
As flatheads get older, they catch more fish. This makes their hunting more efficient. They prefer deep pools and dense wood for hunting.
In these places, crayfish are harder to find. This is why older fish eat less crayfish.
In brackish areas, crabs are also food. But fish are more common because they are easier to catch.
Regional availability and habitat differences
Where you are affects how long crayfish are eaten. In Ozark streams, crayfish are eaten longer. But in murky waters, fish are caught sooner.
Local features like rocks and trees also matter. Places with more crayfish or fish change how much crayfish are eaten. This shows how important habitat is for what fish eat.
Impacts on ecosystems and fisheries
Flathead catfish change rivers and lakes when they move in. Their big size and hunger affect food webs a lot. Anglers love them, but they can upset the balance in streams.
Flatheads as apex predators shaping fish communities
Adult flatheads mainly eat fish. They can eat a lot of food quickly. This changes the age of fish like sunfish and shad.
They also eat smaller catfish. This makes the fish community change. There are fewer mid-sized fish and more fish that hide at night.
Studies show big changes after flatheads arrive. They eat a lot of prey, and it takes a long time for prey to come back. This is true in simple streams.
This can lead to more or fewer insects, depending on what prey is left.
Introductions outside native range and competition with natives
Flatheads have spread across much of the U.S. and Canada. They are not in Alaska, Hawaii, Montana, Utah, or areas northeast of New York. Where they go, they compete with native fish for the best spots.
Agencies report big drops in native fish after flatheads arrive. They eat a lot of food, hurting both common and rare fish.
Management considerations and unintended consequences
Now, managing flatheads focuses on stopping them early. Teams use special tools to track them. They also control fishing methods to protect native fish.
Some want to use flatheads to control other fish. But, this can be risky. Once flatheads are there, it’s hard to control them. This can make things worse for native fish.
| Management Focus | Intended Outcome | Potential Trade-off | Monitoring Tools |
|---|---|---|---|
| Prevent new introductions | Protect native fish communities | Limits on live bait transport may affect anglers | Boat ramp checks, education campaigns, enforcement |
| Contain established populations | Reduce invasive flathead effects | Short-term declines in trophy catch rates | Acoustic telemetry, electrofishing indices, harvest data |
| Targeted removals | Relief for stressed prey species | Bycatch risk and higher program costs | Mark–recapture, CPUE trends, diet studies |
| Regulation balance | Sustain sport value while limiting spread | Complex rules can confuse the public | Angler surveys, compliance audits, outreach metrics |
| Reject predator-based biocontrol | Avoid biological control risks | Slower progress on nuisance fish goals | Risk assessments, scenario modeling, pilot trials |
Angler insights: matching bait to natural prey
To find the best bait for flathead catfish, look at what they eat. They love live sunfish shad, small carp, and bullheads. So, using lively bait is a good idea.
In spring or for fish under 10 inches, crayfish and big nightcrawlers work well. Choose bait that matches what’s around. Shad runs near dams, bluegill hide in brush, and young carp are in backwaters.
Location and timing are key. During the day, fish woody spots like undercut banks and logjams. At night, go shallow with bold tactics.
Summer is the best time, from midnight to dawn, when water is 66–90°F. Crabs in brackish areas might eat crustaceans, but fish baits are more reliable.
Use heavy rigs and be prepared. Flatheads have big mouths and strong bites. Choose stout rods, strong lines, and circle or J hooks. Trotlines and dams are great spots.
Keep your bait selection in tune with the season. Active shad, sunfish near cover, or crayfish in early spring are good choices. This way, your live bait sunfish shad strategy will work day or night.
Be quiet and patient. Place baits close to structure, let them move, and wait for a strong bite. These tactics, used at night and in woody spots, increase your chances of catching big fish.
