When you have a flock of laying hens, the goal is farm-fresh eggs for yourself and maybe a few to sell on the side. But if you want to grow your flock, you'll have to add a rooster to the henhouse, at least for a few days. You -- or your chickens, rather -- will never hatch chicks if a rooster isn't involved at some point.
Necessary to Get Chicks ...
It's one of the most basic facts of life: If you don't have a male and female chicken, you won't get chicks. It's in a hen's nature to lay eggs; you'll usually get eggs whether or not you have a rooster. But unless a rooster is available to mate with your hens and fertilize the eggs, you won't see any baby chicks.
... Not so Much to Hatch Them
Although a rooster's contribution is needed to get things started by fertilizing the eggs, he isn't much help after that. The hen and not the rooster will sit on the eggs for three weeks, turning them over about 50 times a day to keep the insides from sticking to the shells. Once the rooster's done his job, he isn't involved in the incubating and hatching process.
A rooster might not help hatch the chicks by sitting on the eggs or participating in turning them, but once the babies are out of the shell, he will become a champion caretaker. Roosters keep their flocks organized and together. They take the alpha role in a flock, chicks included, locating food and defending those in his charge against predators.
When Your Flock Lacks a Rooster
In "The Chicken Whisperer's Guide to Keeping Chickens," Andy Schneider and Brigid McCrea say owing a rooster as a permanent part of your flock isn't necessary to obtain fertile eggs to hatch chicks. If you know someone with roosters, you could borrow one of those fellows for a week or so. You could even get fertile eggs from the same person or from a local farmer or a hatchery that sells fertile eggs, and have your chickens sit on them until they hatch. You may find, however, that buying fertilized eggs can be more expensive than buying chicks that have already hatched, especially if you want chicks of a rare breed.