Chickens are free to move in barn housing systems and eggs produced this way are labelled cage-free eggs. If desired, organic or free-range eggs can also be produced in barn systems. In barn systems, nine chickens are allowed to be kept per one square meter of space. The perches and litter in barn systems provide the chicken with additional stimulation. Drinkers and feeders are attached to the ceiling and can be lowered and raised with an electric winch depending on the growth of the birds. Covering the floor with plastic slats makes the hen house cleaner. Automated nests provide chickens with a peaceful and dark environment for laying eggs, which results in low incidence of cracks and high amount of clean eggs.