One of the main things that wild chickens do when they get to a certain environment is find a place where they feel safe. This is usually the case in places that have enough food sources and also where there are few to no predators around. The best example of this would be Hawaii.
This is where you can often find wild chickens roaming free. It is a very good environment for them and it also has the right temperature for them.
When it comes to sleeping, the chickens in the wild will find a spot that they feel comfortable with. In most cases, this means they will sleep high up in the trees where they can be protected from a variety of predators. This is particularly important if a hen has eggs that she needs to protect.
The reason why they need to sleep high up is that they are very vulnerable to a variety of nocturnal predators in the wild such as foxes, coyotes, raccoons, skunks, ferrets, marsupials and cats (wild and domestic). The higher they are, the more protection they have.
There are also some chicken breeds such as silkies that can not fly high up to find a good roost so they tend to sleep on the ground. They are able to do this because they have very unique feathers that allow them to be able to perch on something while still being able to rest. The reason they are able to do this is because their wings are tucked under their body and the head is slightly tucked up against them as well. This gives them the ability to keep their eyes open and also the ability to swoop down on any predator that may be near them.