Will a chicken sit on eggs which are duds?

Yes, a hen will sit on eggs that are duds, also known as "addled" or infertile eggs. Here's why:

* Instinct: Hens have a strong instinct to brood and sit on eggs. This is a natural behavior that's been ingrained in them for generations.

* Hormonal Changes: When a hen starts to lay eggs, her hormones change, triggering a broodiness instinct. This instinct doesn't differentiate between fertile and infertile eggs.

* Warmth: The hen will sit on eggs to keep them warm, regardless of whether they're fertile or not.

* Comfort: The act of sitting on eggs can be a comforting and calming activity for a hen.

It's important to note that while a hen will sit on duds, she won't be able to hatch them. She'll spend about 21 days incubating them, only to find that nothing comes out.

If you're worried about your hen wasting time on duds, you can try:

* Replacing duds with fertile eggs: If you have fertile eggs, you can swap them in with the duds to give your hen a chance to hatch chicks.

* Breaking the broodiness: This can be done by removing the eggs and making the nesting area uncomfortable. You can also try using a "broody buster," which is a device that disrupts the hen's sitting pattern.

Overall, it's perfectly natural for a hen to sit on duds. If you want to encourage her to hatch chicks, you'll need to provide her with fertile eggs.