A hen will typically lay 10 to 14 eggs before she sits on them. Hens get off their nests once or twice a day for between 15 and 30 minutes to eat and poop.
Sometimes a hen will abandon the eggs in her nest but there is usually a reason. It could be a young hen in her first season having a false start or she has been disturbed by the rest of her flock or a predator.
Not every hen is cut out to be a good mother.
Broody hens abandon their nests of eggs for the following reasons:
- They have had a fright.
- Vermin like rats.
- Regular disturbance.
- The eggs are infertile.
- Young hen often have false starts and she just stops being broody.
- The weather changes.
Hens tend to become broody in the spring as the weather warms up and if you suddenly get some cold and wet weather it can send the hens off their nests.
I once had three hens leave their nests after a really bad thunder storm with lightning.
I have always been fascinated by a chickens ability to sense whether the eggs are fertile or not and it may be she decided the clutch was not viable.
Hens start sitting on eggs when there is a nest full of eggs in a good spot and she becomes broody.
Rats and mice do go under broody hens and will steal chicks and eggs.
Parasites is a common reason for abandoned nests with the hens literally getting irritated off the nest. Treat both the hen and the nest with diatomaceous earth before sitting commences.
Some hens just never seem to get the idea, I had one that was broody all-day and returning to her perch at nigh.
Flock dynamics and stress factors play a big part in hens behaviour and that can force broody hens off their nests as well.