Brooding in chickens refers to the behavior of a hen that wants to incubate eggs and hatch chicks. When a hen goes broody, she sits on her eggs for an extended period of time, allowing her body temperature to increase and often consuming less food and water than she would normally. Broody hens can be identified by their behavior, which includes staying in the nest all day, becoming territorial over their nest, and plucking feathers from their breast to keep the eggs warm.

Broody behavior is a combination of hormones, instinct, and maturity, and some breeds are more prone to it than others. Silkies are famous for being broody hens, while other breeds that have been known to go broody at times are Australorps, Brahmas, Cochins, Faverolles, Orpingtons, Plymouth Rocks, Sussex, and Wyandottes.

If you want your hens to hatch fertilized eggs, you can let them go broody, but if your primary goal is to collect or sell eggs, you may want to avoid breeds that go broody. Broody hens stop laying eggs and pour most of their resources and body stores into incubating their clutch, and it may take 2-3 months before they start laying again.

If you want to discourage broody behavior, you can try to "break" a broody hen by removing eggs from under her regularly, picking her up and setting her away from the nesting area while you collect them, or using a wire-bottom cage. Some people also slip a few ice cubes under a broody hen a couple of times a day, which can result in cooling her and reducing her broodiness.