I just had my first hen go "broody."  I have to tell you, I can see how it would be pretty annoying, but I thought it was awfully funny.  The first thing I noticed was that she was behaving oddly for several days.  She would do what I called a "turkey impression."  

If you have ever seen a tom turkey puff himself up to impress the ladies, that's pretty much what Ethel did.  She fluffed out all of her feathers, cocked her tail up and fanned out her tail feathers, and wandered around mumbling "tuk tuk tuk" under her breath.

Yesterday I checked the coop around noon and found that she was sitting in the nest.  I closed the door to let her finish her business.  I went back at 5PM and she was still sitting there!  Clearly, she had gone broody.

Broodiness is a trait which has been bred out of most chicken breeds.  If you're a chicken producer, the last thing you want is for your livestock to spend up to a month sitting in the dark, not laying eggs or putting on meat.  Therefore, non-broody hens were selected to continue the lineage.

This is NOT true of silkies, which are now prized specifically because of their broodiness.  If you want a clutch of eggs raised naturally by the hen, then you want a silkie.  

Buff Orpingtons are also less manipulated as a breed than many others.  Ethel is a Buff Orpington, and clearly she had decided to continue that tradition.

If not disturbed, a hen which is brooding eggs will sit on them for up to a month before giving up.  It takes 21 days for fertilized eggs to hatch.  If you don't have a rooster, those eggs can be there a looooong time before the hen finally gives it up on her own!

Brooding hens will only leave the nest once a day.  They will gobble down food and water, poop, then return to their clutch.  It's important that they don't leave more often, because the eggs have to stay warm.  

Because of this, it's best to try and break up a broody hen.  A hen who only eats once a day is not a healthy hen!  If you are trying to brood chicks, you will want to be sure that food and water is kept near the nest.

For many hens, just shooing them off the nest is enough to break the broody streak.  I'm lucky in that I have a rear opening for my nest box, so I was able to get her out by just pushing on her bottom.  The front part of the chicken tends to get a little pecky when eggs are involved.  If you're trying to break a broody hen off her nest from the front, I recommend wearing leather gardening gloves.

If a hen is desperately broody, keeping her in a separate enclosure (with food and water) for a few days will often do the trick.

Another old standard is to put her in a wire crate up above the ground. The air circulation beneath her is what does the trick.  Old parrot cages are excellent for this, as they are nice and spacious. Wire dog cages work as well.  You can hang the cage from the rafters, or set it up on sawhorses or blocks.  There's a great thread with more suggestions on the BYC forum!

Creative Commons-licensed image courtesy of Flickr user swissrolli