What is a battery cage?

A battery cage, sometimes called a conventional cage, is designed to house laying hens, meaning female chickens who produce eggs. After being born in hatcheries, undergoing the process of debeaking, and awaiting maturity (which usually takes about 18 weeks), hens are sent to the battery cages where they will spend the remainder of their lives, which generally last for about two years.

While designs may differ based on country or individual farm, generally battery cages are made of wire on all sides, including the bottom, so that waste falls through to collection troughs below. The floors of battery cages are sloped so that eggs roll down toward the troughs on one end of the cage, where the eggs are then carried away via conveyor belt. A feeding trough is located on the other side of the cage, and while food is generally always available to the birds, they must push their heads and necks through the wire mesh, which can result in feathers on their chests being rubbed off due to constant friction.