Life Cycle
The first sign that your pullets are approaching laying age doesn't come from the birds at all, but from the calendar on your wall. Pullets begin to lay when they are between 18 and 22 weeks of age. Once they've begun to lay, their fertility cycle continues for 50 to 60 weeks before the hens molt and temporarily stop laying. The molt is a time when the birds replenish their bodies' stores of nutrition and rest up for another cycle of egg laying.
Comb and Wattles
The most widely cited signs that birds are preparing to lay are changes to their comb and wattles. As their egg-laying cycle approaches, the birds' wattles and comb become more prominent, growing slightly larger and distinctly redder. If you have a mixed flock, it is more difficult to assess, since different breeds vary in the size and coloration of their combs. Recognize each bird individually to distinguish the changes in coloration and size.
Behavior and Other Physical Signs
Pullets on the verge of egg production begin to behave erratically. They often appear agitated and vocal and they become very territorial as they begin exploring potential nesting sites. If your chickens are pets and accustomed to being pet you may find that your pullets suddenly begin to squat in place when you pet them. Their vents may appear engorged and pink. These are all signs that indicate your pullets are beginning to lay.
Caring for Laying Hens
Once your hens have begun to lay, their appearance begins to change. In breeds that lay brown-shelled eggs, the color of the birds' legs fade in direct relationship with their laying prowess. Their plumage also begins to to look scruffy and battered, as the birds' bodies put all their resources into egg production. It is very important to provide laying hens with a nutritious and well-balanced diet with adequate salt and high levels of fats, protein and calcium. Any shortcomings in their feeding program will impair egg production.