Can Baby Chickens Eat Mealworms? Yes, but Wait Two Weeks

Yes, baby chickens can eat mealworms. Just not in their first two weeks, and not many of them after that. Chick starter is already a complete feed, and every worm a chick fills up on is a bite of starter it doesn’t eat. So think of mealworms as a treat you measure, not as protein your chicks are missing.

I rewrote this page from 15 sources, and you’ll find all of them at the bottom. Most of the feeding rules come from Gail Damerow’s guide for Cackle Hatchery and from university extension sheets. What’s inside a mealworm comes from Feedipedia, a feed database that French research agencies run with the FAO. The trial results come from poultry science papers. When the math is mine, I’ll say so.

A word on the photos. Free, real photos of mealworms are scarce, and I couldn’t find one I could vouch for. So these show chicks, plus one of spoons, and I’ll tell you what each one is as we go.

The short version.

• Wait. Cackle says to feed nothing but starter for at least the first two weeks.
• Keep it small. Cackle caps all treats at 10% of what chicks eat, measured by volume.
• Crush them. Cackle lists mealworms for chicks dried and crushed, and chicks need grit once they eat more than starter.
• Skip the other one. The lesser mealworm, a beetle that lives in old poultry litter, can carry poultry disease, say extension entomologists in Arkansas and Kentucky.

Chick Starter Is a Complete Meal

Gail Damerow has raised chickens for more than five decades, and she wrote Cackle Hatchery’s guide to feeding chicks. Her starting point is blunt: “Chick starter provides all the essential nutrients for proper growth”. Then she goes one step further: “Anything additional that you feed baby chicks will dilute these nutrients and can create nutritional imbalance”.

That second line is honestly the whole reason to go slow with mealworms.

A chick that eats worms eats less starter, and one study found exactly that. I’ll get to it in the trials section.

Her rule for the start is simple: “Feed only starter ration for at least the first two weeks”. After two weeks, treats are fine in small amounts, as long as they never replace the starter. It’s the same rule we gave for fruit and vegetables in Can Baby Chicks Eat Fruits and Veggies?

Purina’s Start & Grow tag says much the same in label language. It’s sold as a complete feed, meant to go to your flock “as the sole ration” from hatch until laying age at 18 to 20 weeks. On its guaranteed analysis, protein is at least 18% and fat at least 3%. Calcium sits between 0.75% and 1.25%. You’ll want those numbers in the next section.

The chick in that photo is fresh out of the shell, asleep on top of eggs that haven’t hatched yet. That’s day one, the day the two-week wait starts counting from.

What’s Inside a Mealworm

A mealworm is a larva, the young stage of a darkling beetle called Tenebrio molitor. A full-grown one is 20 to 32 mm long, about 3/4 inch to 1 1/4 inches, and weighs 130 to 160 milligrams, according to Feedipedia.

Feedipedia also averages lab tests of fresh mealworms. They come out at 41% dry matter, so more than half of a live worm is water. Of the dry part, 53.5% is protein and 35% is fat. Dried mealworms look almost the same on a dry basis: 50.4% protein and 35.6% fat.

Now set that beside the Purina tag you just read. On a dry basis, a mealworm is about half protein and a third fat, and the starter promises at least 3% fat. A tag gives a minimum, not the real figure, so I can’t tell you the exact gap. It’s a big one either way.

Calcium turns out to be the bigger problem.

Feedipedia’s average fresh mealworm has 2.5 g of calcium per kilogram of dry matter, against 7.9 g of phosphorus. By my math, that’s about one part calcium to three parts phosphorus. “Calcium is generally low relative to phosphorus”, is how Feedipedia puts it. And 2.5 g per kilogram works out to 0.25%, a third of the 0.75% minimum on Purina’s tag.

A worm can hold more calcium if it eats some first. Klasing and colleagues at UC Davis kept mealworms in wheat bran with 8% added calcium, then fed them to growing chicks. Judging by bone ash, the chicks got 76% as much use from that calcium as from oyster shell. That’s a lab step.

You can’t do it with a bag of dried worms.

About the photo: I wanted mealworms here. The only free photo of them I found had no other shot from the same shoot to check it against, so I left it out. Those two chicks were at a USDA farmers market in Washington, D.C., for a National Egg Day event in 2017. USDA’s caption calls them day-old chicks.

What the Feeding Trials Found

Every trial I read was done on broiler chicks, the fast-growing meat birds. If you’re raising laying-breed chicks, yours grow slower, so take these as clues, not rules. And the chicks in that photo are in a commercial broiler house in Texas, not in any of the trials.

The oldest is from 1995, by Despins and Axtell at North Carolina State. It used larvae of the lesser mealworm, not the yellow mealworm, but what the chicks did is what matters here. Chicks given both starter and larvae from day 2 to day 9 ate 287 to 631 larvae each per day. They weighed more than chicks on starter alone, and they ate less starter.

Chicks fed nothing but larvae? They did badly. From 3 to 8 days old they ate about 1,552 larvae a day each, and after 6 days they weighed 84 g less than chicks on starter. Put back on starter for 8 more days, they never caught up. At 14 days they were still 170 g lighter, according to the paper.

Newer trials mixed yellow mealworm into a balanced diet. Biasato and colleagues in Turin fed male broilers mealworm meal at levels from 5% up to 15% of the diet, with every diet balanced for protein and energy. More mealworm may raise weight and feed intake, the team wrote, but it hurt feed efficiency, and the 15% birds had shorter gut villi than the controls. Their own conclusion: “low levels may be more suitable”.

A Greek team swapped 5% or 10% of a broiler diet for dried whole larvae from day one, and those birds gained more and scored better on some welfare traits (Vasilopoulos and colleagues, 2023). In Italy, Bellezza Oddon’s group gave broilers live larvae on top of commercial feed from 4 days old. The amount was 5% of each bird’s expected daily feed, counted on a dry basis, and the team found “no negative effects” on growth or health.

Feedipedia sums up the broiler work: the steadiest results come from mealworm meal at around 2.5% to 7.5% of the diet. It also describes a cafeteria-style trial, where broilers could pick from separate feeders. They worked up to eating as much as half their intake as mealworm meal, and they ate less and grew less than birds on a complete diet. Left to choose, they didn’t balance their own plate.

Kinda like kids at a buffet, if you ask me.

Here’s how I read all that. Worms did fine as a measured slice of a balanced diet. They did badly as the whole diet, or when chicks could fill up on them freely. A brooder with a dish of worms in it looks a lot more like that cafeteria trial than like a nutritionist’s formula.

How Much Is 10 Percent?

Two rules agree on the number. Cackle says treats shouldn’t add up to “more than 10% of the chicks’ diet by volume”. For chickens in general, Colorado State University Extension says treats “should make up no more than 10% of their daily diet”.

By volume is the easy way, and that’s why the photo above is spoons, even if those are full of spices. You measure the starter you put out in a day for the whole brooder. A cup holds 16 tablespoons, so a tenth of a cup is about 1.6 tablespoons. If your chicks go through 2 cups a day, the cap for the whole bunch is about 3 tablespoons of crushed worms. That covers every treat, not just worms.

By weight takes a feed chart. In Jacquie Jacob and Tony Pescatore’s table for the University of Kentucky, a dual-purpose pullet’s feed total goes from 1.00 lb at 2 weeks old to 2.24 lb at 4 weeks. That’s 1.24 lb over 14 days, or about 40 grams a day by my math. Leghorn-type pullets eat a bit less, about 37 grams a day by the same math.

A tenth of 40 grams is 4 grams. A full-grown live mealworm weighs 130 to 160 milligrams, so 4 grams is about 25 to 30 live worms per chick per day. Dried worms weigh less each, so 4 grams of them is more worms.

That’s a ceiling, not a target. Honestly, it’s far more than I’d give. The trials that went well stayed at 5% or 10% of the diet, and the Turin team said lower may be better. A few crushed worms per chick as a treat keeps you well under every number on this page. That last part is my opinion, not a study’s.

Dried and Crushed to Chick Size

Cackle’s list of safe chick treats does include mealworms, with two words after them: “Dried and crushed”. I’d take both words seriously.

Crushed matters because your chicks are small. For every treat, Damerow’s advice is “Chop everything into chick-size bits to prevent choking”. A full-grown worm can run 32 mm long. Look at those day-old chicks beside a hen’s egg in the photo, and you can see why.

Grit comes along with it. Cackle says chicks on starter alone don’t need grit, but “when they start eating anything fibrous, they need grit to help with digestion”. Chick-size grit is sold at most farm stores, the guide adds. Jacquie Jacob of the University of Kentucky also notes that commercial grit comes “in chick or hen size”. Feedipedia’s table gives fresh mealworms 12% neutral detergent fiber on a dry basis, a lab measure of fiber, so I’d count them as fibrous and put out chick grit the day treats start.

Leftovers go too. Damerow warns that “moist foods in warm brooder can develop mold and bacteria”, so pull anything the chicks leave in the bedding. Live worms that get away are their own trouble. The University of Florida’s entomology department says the yellow mealworm is a stored-grain pest that hides “under bags of feed” in warehouses, which is one more reason I’d stick with dried ones for small chicks.

The Other Mealworm, in Old Litter

There’s a second insect called a mealworm, and you don’t want this one. The lesser mealworm, Alphitobius diaperinus, is a small beetle that lives in poultry litter. Kelly Loftin, an extension entomologist with the University of Arkansas, and Ricky Corder write that people in the poultry business also call it the litter beetle or the black bug.

It feeds on spilled feed, manure, dead birds and cracked eggs in the litter, their fact sheet says. That’s how it picks up disease. Their list of disease organisms potentially tied to the beetle includes Marek’s disease and Newcastle disease, along with Salmonella and E. coli.

Lee Townsend of the University of Kentucky says it plainly: “Healthy birds can become infected after eating infected larval or adult litter beetles”. He adds that the beetles gather where litter is damp, or looser and deeper. The photo shows the kind of litter floor they live in. Its caption says nothing about beetles, so don’t read any into it.

And yes, chickens like them, too. “Chickens will readily consume beetles instead of feed”, says the Arkansas sheet. That’s the same pattern as in the trials, where bugs crowd out the ration.

The 1995 study above fed this same beetle’s larvae to chicks under research conditions. Larvae from an old coop floor are another matter, because they’ve been eating whatever is in that litter. So I’d brood chicks on fresh bedding and buy worms, rather than let chicks hunt bugs in old litter. If you’re thinking about raising your own, How to Raise Worms for Chickens explains why a closed bin beats the yard.

So Should Your Chicks Get Mealworms?

They can, after two weeks, and in small amounts.

Nothing I read says your chicks need them, though. The trials that went well used measured amounts in a balanced diet, and the ones that went badly let worms crowd out feed.

Here’s what I’d do, pulled from the sources above. Feed only starter for the first two weeks. After that, offer dried, crushed worms as a treat, and keep every treat together under a tenth of the day’s feed. Put out chick grit when treats start, and clear away what they don’t eat.

For a quick check on any other food, try our Can Chickens Eat It? food checker. And for the foods to keep away from chicks and grown hens alike, see What Not to Feed Chickens.

Sources

• Gail Damerow, Cackle Hatchery: What to Feed Baby Chicks (posted July 31, 2026).
• Purina: Start & Grow, guaranteed analysis and feeding directions.
• Feedipedia: Mealworm (Tenebrio molitor) datasheet.
• Feedipedia: Mealworm (Tenebrio molitor), fresh, nutrition table.
• Klasing KC, Thacker P, Lopez MA, Calvert CC: Increasing the calcium content of mealworms to improve their nutritional value for bone mineralization of growing chicks (J Zoo Wildl Med, 2000).
• Despins JL, Axtell RC: Feeding behavior and growth of broiler chicks fed larvae of the darkling beetle, Alphitobius diaperinus (Poultry Science, 1995).
• Biasato I and colleagues: Yellow mealworm larvae inclusion in diets for male broiler chickens (Poultry Science, 2018).
• Vasilopoulos S and colleagues: Growth performance, welfare traits and meat characteristics of broilers fed diets partly replaced with whole Tenebrio molitor larvae (Animal Nutrition, 2023).
• Bellezza Oddon S and colleagues: Black soldier fly and yellow mealworm live larvae for broiler chickens (J Anim Physiol Anim Nutr, 2021).
• Colorado State University Extension: Raising Poultry the Organic Way, Disease Control and Feeding.
• Jacquie Jacob and Tony Pescatore, University of Kentucky: How Much Will My Chickens Eat? (ASC-191, PDF).
• Jacquie Jacob, University of Kentucky, on the Poultry Extension site: Feeding Chickens for Egg Production in Small and Backyard Flocks.
• Kelly Loftin and Ricky Corder, University of Arkansas: Biology and Management of the Lesser Mealworm in Poultry Operations (FSA7081, PDF).
• Lee Townsend, University of Kentucky: Lesser Mealworms or Litter Beetles (ENTFACT-507, PDF).
• University of Florida, Stored Product Pests: Yellow mealworm, Tenebrio molitor.

Sources checked October 28, 2026. Every conversion and per-day figure marked as my math is worked from the numbers above. We aren’t vets. If a chick looks sick, call a vet who sees poultry.

Related read: How to Raise Chickens for Eggs — Instant PDF download. Secure checkout by Stripe