Although egg laying and brooding characteristics of chickens are genetically determined (with some breeds being better layers than others and some hens being more inclined to broodiness than others), all hens perform some amount of nest building and egg laying.
For example, breeds that have been developed for high egg production have also been bred to not be broody; they are least likely to set on a clutch of eggs and brood it naturally.
If nest boxes are supplied with straw, hens will enter the boxes, scratching and pecking at nest material until they form a nice little hollow. After laying an egg, a hen will usually let out a cackle to let everyone know about her accomplishment. If you don’t provide nest boxes, hens may go off under a bush or other sheltered place and create a nest with available material such as straw, grass or weeds.
Chickens prefer laying in nests that already contain eggs. They can also be extremely stubborn about laying in the same location, so if another hen is in a favored nest, you may find two hens crowded together trying to lay in the box at the same time. Broody hens will spend more time in the nest on cooler days and more time off the nest on warmer days, but overall they will get off the nest only for very short periods of time to eat and drink.
Remember, if you don’t have roosters, your hens can sit forever and never hatch chicks, as the eggs are unfertilized. Roosters must mate with hens to produce fertile eggs. For laying hens, place food (primarily scratch grains while she is setting, instead of laying mash) and water near her nest so she doesn’t have to venture far to eat and drink. If you don’t want the hen to set on a clutch, you have to regularly remove all the eggs from under her.
Communicating With Chicks And Monitoring Development
Vocalization is even important during the brooding process. Scientists have discovered (using tiny microphones connected to eggs and placed in the nest) that the hen hears vocal responses from the embryos to her vocalizations. These responses give her clues as to how the embryos are developing compared to each other. Based on that communication, she turns the eggs at different rates—moving one that is maturing a little more quickly out to the edge of the pile to cool off and slow down, while moving one that is maturing more slowly to the center of the nest to speed development.
Broody … Or Not Broody?
Sometimes you’ll see a hen sitting on a nest, but you may not be sure if she is actually brooding. To find out, slide your hand under her and try to remove the eggs. If she is just sitting there, when you reach under her to take the eggs out, she will get off the nest rather indignantly, squawking and fussing the whole time. If she is broody she’ll stay put, pecking your hand and making little, throaty noises while she puffs up her feathers and tries to look tough.