Can Chickens Eat Eggshells? Safe Ways to Reuse Them

Yes, laying hens can eat eggshells. But there is an important difference between tossing a recognizable half-shell back into the run and offering dried, finely crushed shell as a calcium supplement.

If you already use eggs from your own flock in the kitchen, reusing some of the shells can make sense. It is optional, though. Your hens do not need recycled eggshells if they already receive an appropriate complete layer ration and have access to another suitable calcium source such as oyster shell when needed.

The safest approach is simple: keep the main diet balanced, dry used shells well, crush them so they no longer resemble an egg, and offer supplemental calcium separately rather than mixing extra calcium blindly into the flock’s feed.

Why Laying Hens Need So Much Calcium

An eggshell is mostly calcium carbonate, so a laying hen has to move a large amount of calcium into each shell she produces.

Layer feeds are formulated with more calcium than chick starter or grower feeds. Oregon State University Extension notes that typical layer feeds contain roughly 3 to 4 percent calcium. Some high-producing hens may still benefit from supplemental oyster shell offered separately.

That is the key nutritional point for this article: recycled eggshells are a supplement, not a replacement for a complete laying-hen ration.

If your flock includes chicks, growing pullets, roosters, or non-laying birds, do not turn the whole feed ration into a high-calcium mix just because some hens are laying. Use the correct complete feed for the birds involved and offer supplemental calcium separately where appropriate.

For the larger feeding picture, see how to feed chickens.

Eggshells vs. Oyster Shells: Which Is Better?

Both can supply calcium, but oyster shell is usually the easier and more consistent option for a backyard flock.

Commercial oyster shell is already prepared for poultry use, stores well, and can be kept in a separate small feeder. Recycled eggshells depend on how many eggs your household uses, how carefully you prepare the shells, and whether you have enough to make the effort worthwhile.

You do not have to choose only one. Some keepers reuse household eggshells when they have them and keep oyster shell available as the more dependable backup.

Whichever calcium source you use, keep it separate from the main feed rather than automatically mixing extra calcium into every mouthful. Oregon State recommends a separate feeder for free-choice oyster shell, which lets laying hens take supplemental calcium without forcing the same amount on every bird.

How to Prepare Eggshells Before Giving Them Back to Hens

You do not need a complicated “sterilization” routine or a magic oven temperature.

Penn State Extension’s egg-eating guidance gives the two practical steps that matter most: dry used eggshells and smash them into very fine particles before feeding them back.

1. Start with shells from normal kitchen eggs. Do not reuse shells from spoiled eggs or shells that are heavily contaminated with manure or dirty nest material.
2. Remove obvious egg residue. If a shell still has a lot of yolk or white attached, rinse or wipe away the residue and keep kitchen surfaces clean afterward.
3. Dry the shells completely. You can let them dry in a clean place or use gentle oven heat as a drying step. Drying makes them easier to crush and store. It should not be described as a guaranteed household sterilization process.
4. Crush them very finely. The finished pieces should no longer resemble halves or large fragments of an egg.
5. Store them dry. Keep crushed shell in a clean, dry container until you are ready to offer it.
6. Offer a small amount separately. Do not replace the complete ration with shells or mix large quantities into feed.

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There is no need to measure every fragment to an exact millimeter size. The practical goal is to make the shell dry, easy to eat, and difficult for a hen to recognize as part of an intact egg.

Will Feeding Eggshells Make Hens Start Eating Their Eggs?

Feeding properly prepared eggshells does not mean your entire flock will suddenly become egg eaters.

Broken eggs are still worth taking seriously because once a hen learns that the contents are edible, the behavior can become difficult to manage. Penn State therefore recommends drying used shells and smashing them into very fine particles so the hens are less likely to associate the supplement with an intact egg in the nest.

That is much more realistic than saying one accidental peck guarantees a permanent habit or that every other hen will copy it.

Egg eating is also more likely when eggs are already being broken. Thin shells, overcrowded nests, not enough nesting space, bright nest areas, or birds stepping on eggs can all create opportunities for the behavior to start.

If you are seeing frequent broken eggs, fixing the cause matters more than simply stopping the use of recycled shells.

What to Do When an Egg Breaks in the Coop

A freshly broken egg should be cleaned up rather than left in the nest box or litter.

1. Remove the broken shell and as much yolk and albumen as you can.
2. Take out bedding that is wet or coated with raw egg.
3. Replace the area with clean, dry nesting material.
4. Check whether more than one egg is breaking in the same nest.
5. Look at shell quality. Repeated thin or fragile shells deserve a feeding and health review.
6. Check the nest-box setup for crowding, hard surfaces, awkward entry, or hens sleeping in the boxes.

Do not assume every cracked egg means the hen needs more calcium. Shell problems can involve age, nutrition, disease, stress, heat, and disturbances during shell formation. See the soft-shelled egg guide if abnormal shells are becoming a pattern.

What About Salmonella on Eggshells?

Backyard poultry and their eggs can carry Salmonella and other germs, which is why normal hygiene matters whenever you handle eggs, chickens, litter, or coop equipment.

That does not mean every shell from your own kitchen creates a guaranteed “reinfection cycle” if it goes back to the flock. The risk depends on the flock, the egg, contamination, handling, and the organism involved.

Use common-sense hygiene instead of pretending one household baking temperature makes a contaminated shell sterile. Wash your hands after handling raw egg residue or poultry materials, clean kitchen surfaces, and do not feed visibly spoiled or heavily soiled shell material back to the birds.

If your flock is dealing with a known infectious disease problem, follow veterinary or diagnostic guidance rather than using a general eggshell-recycling routine.

Do Not Feed Eggshells to Wild Birds Near the Coop

Some older backyard advice recommends putting crushed eggshells out for wild birds during nesting season. That is not a practice I would encourage around a poultry property.

USDA APHIS recommends reducing contact between domestic poultry and wild birds because wildlife can introduce infectious disease. Its current biosecurity guidance also advises against feeding wild birds or other wildlife on poultry properties.

If you keep chickens, the better goal is to make feed, water, and other food sources less attractive to wild birds and rodents, not more attractive. See the backyard chicken biosecurity guide for the broader flock-safety steps.

Can Eggshells Go in Compost?

Yes. If you do not want to feed eggshells back to the flock, compost is a simple alternative.

Crushing the shells first gives you smaller pieces to mix through the pile. Do not expect them to correct a garden calcium problem immediately, though. Eggshell calcium breaks down gradually and is not a quick treatment for plant disorders such as blossom-end rot.

Keep kitchen scraps and raw egg residue in a managed compost system rather than dumping them beside the coop where rodents, raccoons, or other wildlife can investigate.

When You Should Just Throw the Shells Away

Reusing eggshells is optional. There is no reason to save every shell.

• discard shells from rotten or foul-smelling eggs
• discard shells heavily covered in manure or dirty nest material rather than trying to turn them into a feed supplement
• discard shell material mixed through badly contaminated coop bedding
• follow veterinary guidance if the flock is being investigated for an infectious disease
• use ordinary household trash or an appropriate compost system if you simply do not want to process the shells

You are not wasting an essential poultry nutrient by throwing some shells away. A properly formulated ration and a dependable supplemental calcium source are far more important than recycling every shell your household uses.

FAQs

Final Thoughts

Reusing eggshells can be a simple way to return some calcium to laying hens, but it does not need to become a complicated sanitation project.

Use a complete ration first. If you reuse shells, dry them well, crush them very finely, and offer them separately. Keep oyster shell available when you want a more dependable supplemental calcium source.

And when a shell is badly soiled, comes from a spoiled egg, or is mixed through dirty coop bedding, there is nothing wrong with discarding or composting it instead.

Sources

• Penn State Extension: Prevention of Egg Eating in Chickens
• Oregon State University Extension: How to Feed Your Laying Hens
• USDA APHIS: Protect Your Flock From Avian Influenza
• USDA APHIS: Improving Biosecurity With Wildlife Management Practices
• CDC: Backyard Poultry

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