You can see how many are caged together, the feed trough at the front, and that the eggs they lay are somehow rolled down into that gutter, which may also be a conveyor belt, I don't know.
This is why you hear the term "free-range" about eggs that come from chickens allowed to walk around outdoors, socialize and peck their food naturally. Birds are quite intelligent, and the cage system must be hell on earth for them.
