Why didn't my eggs hatch on day 22?

Most likely your incubator ran slightly cool, which slows embryo development and pushes the hatch late — Mississippi State Extension notes cooler incubators 'tend to produce late hatches.' Day 21 is an **average**, not a deadline. Keep the incubator closed at lockdown humidity and give chicken eggs until **day 23–24** before concluding anything.

How long should I wait past the hatch date before giving up?

Give **chicken eggs until day 23–24** and **duck eggs a few days past their due date** (about day 28 for most ducks, day 35 for Muscovy) before deciding an egg has quit. Beyond that, hatch success drops sharply and the risk to any chick that does emerge rises.

How do I safely check an egg that hasn't pipped?

Candle it in a dark room: a live late chick shows a large dark mass, a drawn-down air cell, and sometimes movement or an internal pip. A blood ring, loose sloshing contents, or a bad smell point to a dead embryo. **Avoid the float test** — wetting the shell late can drown a viable chick — and never crack a shell open on a hunch.

Can eggs still hatch on day 23 or 24?

Yes. Healthy chicks regularly hatch on **day 22, 23, and even 24**, especially from a cooler-running incubator. Later hatchers can be a bit weaker and lose more shell moisture, so leave them undisturbed and warm — but a late hatch is not a failed hatch.

My duck eggs didn't hatch on day 28 — is that normal?

Usually, yes. Common duck eggs are due around **day 28** and Muscovy around **day 35** (Cornell Duck Research Laboratory), and a one-to-three-day delay is normal if the temperature wasn't perfect. Apply the same rule you'd use for chickens: hold conditions steady and give a few extra days before candling to check for movement.

What should I change so this doesn't happen next time?

Calibrate your thermometer and hygrometer before the next set, and confirm the eggs sit at **99.5–100°F** (forced-air) with humidity managed to the air-cell size. A late hatch is almost always a slightly cold incubator or an uncalibrated gauge, plus avoidable temperature swings from drafts or an unstable room.

My Eggs Didn't Hatch on Day 22 — What Now?

Verified September 2026

The short version

Don't intervene yet. Hatching is a window, not a deadline — chicken eggs are due at day 21, and a cool-running incubator routinely pushes healthy chicks to day 22, 23, or even 24. Keep the lid closed, hold lockdown humidity (65–75%) and temperature, and wait. Only consider a candle-check for movement after day 23–24 with no pip. Duck eggs (28 days for most, 35 for Muscovy) run proportionally later.

Hatching is a window, not a deadline

The '21 days' printed on your incubator is an average, not an alarm clock. Mississippi State University Extension notes that an incubator running consistently cool 'tends to produce late hatches' — and most home incubators run a fraction of a degree cold once you account for thermometer error. A hatch that spreads across days 21 to 23 is completely normal, and stragglers reaching day 24 can still be strong, healthy chicks.

So the single most important thing to do on day 22 is the hardest: nothing. Keep the incubator closed, keep humidity up at the lockdown range of 65–75%, and resist the urge to crack the lid 'just to check.' Every time you open a locked-down incubator the humidity crashes, and a chick that has already pipped can shrink-wrap in the drying membrane. Patience through days 22–23 saves more chicks than any intervention.

The same logic scales to other species. Duck eggs are due around day 28 (about day 35 for Muscovy per the Cornell Duck Research Laboratory), so a duck egg that is quiet on its day 28 deserves the same one-to-three-day grace you'd give a chicken on day 21.

When (and how) to check a silent egg

If you're past day 23–24 for chicken eggs (proportionally later for waterfowl) with no external pip and no peeping, you can candle a suspect egg to gather information — without opening the incubator wide or cracking any shells. In a dark room, hold a bright candling light to the large end near the air cell. A live, late chick usually shows a large dark mass filling the egg, a clearly drawn-down air cell, and sometimes visible movement or an internal pip (the beak's shadow poking into the air cell). A dead or quit embryo often shows a blood ring, a loose sloshing mass, or contents that have pulled away and gone murky.

The old 'float test' — setting an egg in warm water to watch for bobbing or wiggling — is sometimes suggested, but treat it with real caution: wetting a shell late in incubation can clog the pores and drown a viable chick, and a false negative tempts people to discard a living egg. Candling for movement and air-cell shape is safer and more informative. If an egg ever smells foul or oozes, it has gone bad — remove it promptly before it can burst and contaminate the rest of the hatch.

Do not assist-hatch or open an egg on a hunch. Assisting too early, before the chick has absorbed its yolk and the shell membrane veins have receded, causes fatal bleeding. If you truly suspect a chick is trapped and overdue, that is a judgment call best made with an experienced hatcher or a vet — not a first move on day 22.

Late versus truly dead

The honest answer is that you often can't be certain until several days past the due date. A useful rule: give chicken eggs until day 23–24 and duck eggs a few days past their 28-day (or 35-day Muscovy) due date before concluding an egg has quit. Signs that point to still alive: a tight, well-defined dark mass on candling, a normal-sized air cell, response (rocking or peeping) to gentle handling, or a visible internal pip. Signs that point to dead: a blood ring, free-moving liquid contents, a bad odor, or an egg that has stayed stone-silent well past the grace window while siblings have hatched.

Even genuinely late hatchers carry higher risk — the longer past the due date, the more shell moisture is lost and the greater the chance of infection at the navel, so a day-24 chick may need extra warmth and rest. If a late-hatched or assisted chick seems weak, unabsorbed, or unwell, this is a health-care question, not a hatching one: consult a poultry veterinarian or the resources at PoultryDVM (https://www.poultrydvm.com) rather than attempting any treatment yourself.

Why it happened — and fixing it next time

A late hatch is almost always a temperature story. Because embryos develop faster when warmer and slower when cooler, an incubator running even half a degree cold across three weeks accumulates into a hatch that slips a day or two late — exactly the pattern Mississippi State Extension describes. The usual culprit is not a broken incubator but an uncalibrated thermometer: the built-in display reads 99.5°F while the eggs actually sit at 98.5°F.

Before your next set, verify your instruments. Check your thermometer against a second known-good thermometer (or a quick ice-water and body-temperature sanity check) and confirm the eggs sit at 99.5–100°F in a forced-air incubator (100.5–102°F measured at the top of the eggs in a still-air unit), with humidity managed to the air-cell size rather than a fixed number. Other contributors to slow or failed hatches include big temperature swings from drafts or a fluctuating room, chronically low humidity that leaves membranes tough and leathery, and shipped eggs whose jostled air cells set them up to lag or fail regardless of your settings.

Common pitfalls

Giving up at day 21 (or day 28 for ducks) — the due date is the start of the window, not the end.
Opening the incubator during lockdown to 'check,' which drops humidity and can shrink-wrap a pipped chick.
Relying on the float test late in incubation — wetting the shell can drown a viable chick; candle instead.
Assisting or opening a shell early, before the yolk is absorbed and shell veins have receded, causing fatal bleeding.
Trusting the incubator's built-in thermometer instead of calibrating against a known-good instrument.

Frequently asked questions

Why didn't my eggs hatch on day 22?: Most likely your incubator ran slightly cool, which slows embryo development and pushes the hatch late — Mississippi State Extension notes cooler incubators 'tend to produce late hatches.' Day 21 is an average, not a deadline. Keep the incubator closed at lockdown humidity and give chicken eggs until day 23–24 before concluding anything.
How long should I wait past the hatch date before giving up?: Give chicken eggs until day 23–24 and duck eggs a few days past their due date (about day 28 for most ducks, day 35 for Muscovy) before deciding an egg has quit. Beyond that, hatch success drops sharply and the risk to any chick that does emerge rises.
How do I safely check an egg that hasn't pipped?: Candle it in a dark room: a live late chick shows a large dark mass, a drawn-down air cell, and sometimes movement or an internal pip. A blood ring, loose sloshing contents, or a bad smell point to a dead embryo. Avoid the float test — wetting the shell late can drown a viable chick — and never crack a shell open on a hunch.
Can eggs still hatch on day 23 or 24?: Yes. Healthy chicks regularly hatch on day 22, 23, and even 24, especially from a cooler-running incubator. Later hatchers can be a bit weaker and lose more shell moisture, so leave them undisturbed and warm — but a late hatch is not a failed hatch.
My duck eggs didn't hatch on day 28 — is that normal?: Usually, yes. Common duck eggs are due around day 28 and Muscovy around day 35 (Cornell Duck Research Laboratory), and a one-to-three-day delay is normal if the temperature wasn't perfect. Apply the same rule you'd use for chickens: hold conditions steady and give a few extra days before candling to check for movement.
What should I change so this doesn't happen next time?: Calibrate your thermometer and hygrometer before the next set, and confirm the eggs sit at 99.5–100°F (forced-air) with humidity managed to the air-cell size. A late hatch is almost always a slightly cold incubator or an uncalibrated gauge, plus avoidable temperature swings from drafts or an unstable room.

Sources

Important incubation factors (temperature, humidity, late hatches) — Mississippi State University Extension Service (University extension)
Hatching Duck Eggs (28-day common / 35-day Muscovy, candling) — Cornell University Duck Research Laboratory (University extension)
Avian Embryology (day-by-day embryo development for candling) — eXtension — Poultry (University extension)