Quick Answer: A broody hen stops laying, flattens herself on a nest, puffs up, growls or pecks if you reach toward her, and leaves only briefly once a day to eat and drink — all driven by a rise in the hormone prolactin. Left alone she’ll sit for the full 21-day incubation cycle whether or not the eggs are fertile, costing roughly 8-10 eggs per cycle according to Mississippi State University Extension. From there you have two options: let her hatch real fertile eggs, or break the behavior with a cooling wire-floor setup so she’s back to laying within days instead of weeks.
Chicken keepers usually notice broodiness the same way: a hen who was laying normally suddenly disappears into the nest box and won’t come out. It’s not illness and it’s not a punishment for anything — it’s a hormonal switch that tells her body to stop producing eggs and start incubating whatever is (or isn’t) underneath her. This guide covers how to recognize it, why some breeds do it constantly while others almost never do, and how to decide between the two real responses: let nature run its course, or intervene.
Signs of a broody hen
| Sign | What it looks like | How it differs from normal |
|---|---|---|
| Refuses to leave the nest | Sits flat, low, and still for most of the day | Normal hens lay and move on within minutes |
| Puffed feathers | Fluffed up to look larger, flattened against the nest | Not the same as fluffing from cold or illness |
| Growling / pecking | Low growl or aggressive peck if you reach near her | Uncharacteristic for otherwise calm hens |
| Plucked breast feathers | Bare patch of down lining the nest | She's lining the nest and exposing her brood patch |
| Egg-laying stops | No new eggs from her while she's sitting | Her body has shifted out of laying mode entirely |
| One big daily dropping | Unusually large, strong-smelling "broody poop" | Result of holding it in while sitting most of the day |
By the numbers
- Left uninterrupted, a broody hen sits for the full 21-day natural chicken incubation period regardless of whether the eggs underneath her are fertile, viable, or even present — the behavior is hormonally driven, not a response to actual hatching progress.
- Mississippi State University Extension puts the cost at roughly 8-10 eggs lost per broody cycle, on top of the multi-week gap in laying itself; extension sources estimate a full cycle runs 4-7 weeks once you count the days broody before and after the 21-day sit.
- Keeper guidance generally flags more than 15-20% body weight loss, along with a pale comb/wattle and lethargy, as the threshold where a long broody sit has crossed into dehydration and malnutrition risk that needs intervention.
1. Confirm it’s actually broodiness
Digital Kitchen Scale (for weight checks)
- A hen who's genuinely broody sits flat, growls or pecks when disturbed, and has stopped laying — a hen that's simply resting, sick, or egg-bound can look similar at a glance but won't show the full pattern.
- Weighing her at the start of a sit and again a week later is the simplest way to catch the 15-20% weight-loss threshold before she gets seriously dehydrated.
- If she's lethargic, pale-combed, or not eating/drinking at all rather than just less, that's a vet or extension call, not routine broodiness.
Before deciding what to do, rule out anything that isn’t simple broodiness. A hen that’s genuinely broody shows the full pattern — flattened posture, puffed feathers, growling or pecking when you reach near the nest, a bare brood patch, and a total stop in her own laying — not just one symptom in isolation. A hen that seems reluctant to move but is otherwise eating normally, or one that’s straining without producing an egg, is more likely dealing with something else, like being egg-bound, and needs different attention entirely.
Restocking a scale or spare waterer before broody season hits your flock? Try Kindle Unlimited free for backyard-chicken reference guides and troubleshooting reading you can pull up anytime you’re not sure what you’re looking at.
2. Know why she’s doing it
Broodiness is driven by a rise in the hormone prolactin, which triggers the nesting instinct and produces a bare, warm patch of skin on the hen’s abdomen — the brood patch — that lets her body heat directly warm whatever is underneath her. Some breeds are dramatically more prone to it than others: Silkies, Cochins, and Orpingtons are notorious for going broody repeatedly through a season, while most modern production hybrids and Leghorns have had the instinct bred out almost entirely, since a broody hen stops contributing eggs, which cuts directly against commercial laying performance. If you picked a heritage or ornamental breed for looks or temperament rather than peak egg output, broodiness is simply part of the package.
3. Decide: let her hatch, or break it
This is the fork every broody hen forces you into. If you have fertile eggs — from your own rooster or shipped/local fertile stock — and actually want chicks, let her sit; she’ll do essentially all the incubation work herself for the full 21 days, and you can candle the eggs partway through to check progress using the method covered in our egg candler guide. If you’d rather pull the eggs and control temperature and humidity more precisely, our chicken incubator guide covers that path instead, with a chicken brooder ready for once they hatch.
If you don’t want chicks, or she’s sitting on nothing but the occasional egg she’s absorbed from flockmates, breaking the behavior is almost always the better call. Left alone she’ll burn through the full 4-7 week cycle for nothing, losing 8-10 eggs of production and risking the weight loss and dehydration that come with a long, low-intake sit. Our broody breaker cage guide covers the standard fix — an elevated, wire-floor enclosure that cools the brood patch and interrupts the hormonal signal — which typically gets a hen back to laying within 3-4 days instead of weeks.
4. Watch for the recurring pattern
A hen most often goes broody in the same shared nest box every time, which is worth checking against our best nesting box guide if it keeps happening in the same spot — collecting eggs more often and keeping the box less “full-looking” reduces the trigger. Repeat offenders, especially in Silkie, Cochin, or Orpington flocks, are also a sign that a permanent broody-breaker setup kept ready year-round beats improvising a new one every time.
The bottom line
A broody hen isn’t sick — she’s a hen whose hormones have flipped fully into incubation mode, and the signs (flattened posture, puffed feathers, growling, a stopped egg count) are unmistakable once you’ve seen it once. From there the decision is simple: let her hatch real fertile eggs if you want chicks, or break the behavior with a cooling wire-floor setup if you don’t, since 21 days of sitting on nothing costs real eggs and, if it runs long enough, real weight off the hen herself.