See the difference between cage-free egg production and battery-cage egg production.

Scientists have just begun to scratch the surface when it comes to understanding bird brains. But studies have shown what backyard chicken caregivers already know: The world’s most most intensively farmed animal has remarkable cognitive abilities.

Around the world, animals used for meat, eggs and dairy often suffer on factory farms where they are treated as units of production rather than living, feeling creatures. The Humane Society of the United States and Humane Society International present comprehensive reports on animal agribusiness and...