Deep litter is a method of keeping your coop/hen house.
It is 6-8-10 inches of pine shavings. It keeps the hen house cooler, and cleaner. There are several forums/posts about it on this website. I use it in my hen house. I also sprinkle a little DE and Stall Dry on it about every 2 weeks, to keep the smell/flies down.
I also use some 5 % Sevin Dust to keep it free of mites/flies/other pests.
Look up subjects of interest on the Search section of this website. It has lots of good information and you don't have to wait for an answering post.
Good luck,
DonnaBelle