If you watch a chicken (or in most cases chickens because they like to be in a group) for any length of time, you will notice that given the opportunity, they will dig a hole.
Why do chickens dig holes?
Chickens dig holes for the following reasons:
1. Chickens are industrious and need something to keep them occupied all day long;
2. Chickens are searching for worms, bugs, and dirt that looks tasty;
3. Chickens are trying to flick dirt up into their wings to help keep their wings dry and remove pesticites;
4. Chickens are trying to create a nice, comfortable nest to lay their eggs;
5. and, sometimes I think Chickens just want to dig
Backyard Chicken Coops