A broody hen is either a wonderful or a terrible thing depending on who you ask. If you're interested in breeding your chickens, a broody hen or setting hen as they are sometimes called is the most natural way to incubate eggs.
If you just want eggs and don't have any fertile ones, a setting hen can be irritating. You see, a hen in this state is going to sit on her eggs regardless of fertility and she's going to be extremely unhappy if you try to move her or take them away from her. She will also quit laying for at least 2 months, possibly more, if allowed to set.
One of the big questions among people who raise chickens is whether or not to let a broody hen stay that way. If you want to get the most egg production out of your hens, disrupting her broodiness, if possible, is a good idea.
Heritage or non-Production breeds are the most likely to go broody. Production bred hens are just that, bred for the most egg production. These have a short healthy life and commercially are replaced after their first and best year of laying then used for meat.
If you want to hatch a batch of chicks you may wish to let her go through the cycle which takes about twenty-one days. You can also prevent broodiness in the first place as long as you know what you're doing.
To keep a hen from setting, you'll need to avoid letting eggs collect in a nest. This collection of eggs triggers broodiness. If it's too late to do this, you can move her from the nest, put her in her own coop, or cover the nest so she can't get in.
You can even use a “broody coop” – a hanging cage made from wire that will house her until she gives up sitting on the eggs (this helps cool-off her underside which breaks the broody hormone cycle). The longer you take to break her of her broodiness the longer it will take her to lay again.
Of course, if you're breeding chickens for meat or for fun, you can collect the eggs from all your birds and let the hen sit on as many as she can handle at once.
This will depend on the size of the hen and the size of the eggs. 8-12 eggs in a clutch is the average. She'll incubate them just as effectively if not more than an incubator with a bonus; you’ll need no brooder to keep the chicks warm until they are fully feathered and nearly half grown, if she is a good mother (not all hens are).
Natural incubation is usually only effective in the spring and summer, when hens go broody, so hatching at other times of the year will require artificial incubation. Using a broody hen that wants to be a mother can be an excellent way to raise baby chicks.
For best results the hen and chicks will need to be housed separately from the rest while the babies are growing up. There are exceptions to every rule and many flocks with a large yard and safe place for chicks and hen on the ground at night naturally accept and don’t bother chicks being raised by a hen.
Chicks raised away from the flock often shouldn’t be introduced to the flock until they are near adult size. This can take a few months depending on the breed’s growth rate.
Some people hatch the chicks under a broody hen, then raise them separately. Either way, make sure that your hen has plenty of food and water - some may not move off the nest to eat or drink for weeks, especially in cool weather.
Taking a setting hen off the nest once a day, offering food and water, will help her stay healthy through the 21 day incubation process.
Knowing which breeds are likely to become broody will let you avoid a setting hen if you want mostly eggs, or choose one just for this trait if you want to produce chicks. Whether a broody hen is a great thing or an awful one depends on what you want to do with your chickens.