A hen will go "broody" at anytime during her egg laying years. Not all hen do and some breeds are just naturally brooders. To ensure at least one brood hen in the flock you might consider getting a Cochin or a Silkie hen as these two breeds are good brooders. There is no way to force a hen to sit on eggs.
Yes, not all eggs hatch even when a brood hen tends them. "Fake" eggs are available for use when a breeder needs a hen to hatch only a very few eggs. The hen will care for any egg in the nest when she broods.
Yes, the hen is careful not to squash the chicks. Hens sit on the clutch of eggs for three weeks without crushing them. Once the chicks start to hatch the hen is extra careful and often gets adjusts her position. The hatching chicks will stay under the mother hen for a few days and even when they venture out, they will dive back under her for protection.
The hen is likely broody, which means she is trying to hatch her eggs. She will sit on the nest to keep the eggs warm and may squawk to protect them. It is a natural behavior for hens to be protective of their eggs and offspring.
It depends on the size of the hen.. But most probably 10 or 11.
yes
You can take them as soon as they are laid. Usually the hen moves off the nest and leaves the egg. However, if she is broody, then she may sit on it hoping to hatch it. If that is the case, just gently reach beneath the hen and remove the egg. She may peck at you, but that's OK. Once the egg is gone, she'll then give up and move away.
It will sit until the others all hatch and leave any that don't hatch.
To keep them warm so they can hatch.
They sit in the hen house on eggs, on the roost or in a nest.
Well to hatch any egg you need warmth. Either you let the mother hen (or a surrragate mother) sit on the eggs until they hatch, or you can incubate them. They usually take an average 21 days to hatch. It can be risky letting a hen sit on eggs, because some chickens (particularly silkies) will sit on the eggs for so long they forget to take breaks for food and water. All you can do is wait and see. If her condition is deteriorating too quickly. Take the eggs from her. Other than that, silkies are one of the best breeds for hatching and rearing eggs!
Sometimes, she will usually wait to sit when there are many eggs.
You need to start with a fertilized fresh egg. An incubator, thermometer and hydrometer would also be handy. You also need to be able to devote at least 21 days to the care of the hatching eggs. A live broody hen would do all this for you.