At night it is a natural instinct for your chickens to perch or roost as high above the ground as they can, as this gives them a sense of safety from predators. Ideally, perches should be at least one or two feet in the air, with around nine inches of space around them. If you can it is a good idea to have perches higher than two feet , but always ensure that you have a ladder like arrangement so that the chickens can jump from one to another as they ascend and descend, to prevent them injuring themselves. However make sure these are not directly below each other as you don’t want roosting chickens pooping on each other during the night. Perches should also be higher than the nest boxes to discourage the chickens from roosting there as you don’t want unnecessary mess where the eggs are laid.
However, perches made from plastic or metal piping are not suitable for chickens, as they cannot grip the perch properly. In fact, chickens prefer to perch on a flat surface with gently curving edges so that their feet are protected as they grip onto the perch. In colder climates flat surfaces are better as they make the chickens sit on their feet and therefore keep them warmer. The perch should be about 2.5 to 4 cm (1″ to 2″ inches) in diameter depending upon whether you are providing for bantams or regular sized chickens. You can also use tree branches which will give your hen-house a more natural look. Always make sure that there are no rough edges on the perches which can injure their feet, as abrasions can quickly lead to infections and result in problems such as bumblefoot.
You should be able to easily remove your perches for cleaning and they should be positioned well away from food or water, as chickens create over 65% of their daily droppings during the night. Some people use trays under the perches which they clean out in the morning as part of their daily routine, alternatively plastic sheeting can be laid down, both of which make keeping the chicken coop clean easier. It is also common in larger sheds or outbuildings to use a built-in droppings pit or box with slats or mesh over it to collect the waste from under the perches.
If you have young chicks as they get older they should start to leave the nest box and perch at night of their own accord as long as the perch is higher than the nest box.