It's not uncommon for a laying hen to go broody, especially in the early spring and summer months. For those who need to refresh your flock, try allowing the hen to sit on a clutch of eggs (usually 10 to 14), and let them hatch out naturally into fluffy baby chicks. Acquire a rooster, so that the eggs are fertilized, or try purchasing or trading for some fertilized eggs.
Finding a Broody Hen
Buff Orpingtons are a breed known for their broodiness. The photo above is a Buff Orpington mama hen with several of her chicks. She will not only hatch all her chicks, but she will also care for them through cold nights, meaning there will be no need for her owner to fuss with a heat lamp. The chicks shown above are a mix of Speckled Sussex and Buff Orpingtons.
One thing to note when mixing breeds is that it's possible to do this successfully with two purebred chickens, but if the next generation interbreeds, it may lead to some very unsatisfactory results.
Also, some hens just aren't good broodies. They yield a smaller hatch rate or have some failed hatches with this method.
Care of a Broody Hen
Just let her sit on the eggs in the nest box, but know that it's best to move her and the clutch of eggs to a larger nest box that measures at least one-foot square. A nest box of this size will allow the hen to turn around, move a bit, and set up for the chicks. She will ensure that, once they hatch, the chicks will have enough room to access food and water within reach of the nest box. At that point, she will be cozy and will not want to be moved. She will most likely peck if anyone tries to move her. Make sure that the floor of the nest box has soft cushioning like shavings or straw. And you will want to make sure that she can't be messed with by the other hens. Put the feed and water right in front of the box for her throughout the duration of her setting, but be sure it is located where she can't knock it over into the eggs. She will only get off the eggs once a day to poop, eat, and drink.
Chicks take 21 days to hatch, and a clutch of eggs can take a few days to completely hatch. Mark the date on your calendar.
Any adjustments that need to be made should be done at night when she is sleepiest. She will defend those eggs and baby chicks as best as she can, and she can peck quite hard.
Right around day 21, the little peeps of baby chicks will be audible. It may be a while before the farmer will get a good look at them. They tend to stay under mama for one or two days. And remember, some will hatch and then the rest may hatch over the next two to four days. After this time, the rest of the eggs are probably not viable. Go ahead, and try to remove any remaining eggs from under the broody hen if possible.
Care of the Baby Chicks
Unlike when chicks are ordered from a hatchery, baby chicks, who are hatched naturally under a broody hen, don't need a lot of care. The mother hen provides the heat, so a heat lamp won't be needed. She will also show the chicks how to eat and drink. Know that the farmer will still have to provide basic chick supplies regardless. The hen will regulate the chicks' temperature naturally by going all the way under her wings or poking their adorable little heads out from underneath her. If she feels there is a threat, she will make a certain clucking noise, and they will all gather underneath her body for safety. They can walk around under her wings and snuggle up together without much of a problem at all.
Just make sure, like with any chicks, that they have fresh feed and water at all times. Try moving them to a brooder area with mama once they've all hatched and are a couple of days old, to give them some room. If possible, leave the brooder partially uncovered so that the mother hen can leave the brooder from time to time. Put a little ramp so they can follow her—but be careful. Observe to make sure that the rest of your flock is not aggressive toward the baby chicks.
Once they're big enough, they'll fly right out of the brooder to follow the mother hen. By six weeks, they won't need to be sequestered anymore and can be introduced to the rest of the flock. Do this at night, just before dark, to minimize aggression, and watch carefully.
Don't get discouraged if the broody hen doesn't hatch any eggs. Many hens lack the natural instinct to hatch a clutch of eggs. They may leave the nest for too long and let the eggs get too cool or not sit on them long enough (maybe they stop after two weeks, for example). But some hens do have enough mothering instinct to provide healthy, adorable, fluffy baby chicks to add to the flock.
Raising Backyard Chickens for Eggs. University of Florida.