Other chickens walk around the bale browsing around the edges of the bale, and eating the alfalfa flakes that get scratched off onto the ground by the upper chickens. Alfalfa is a very nutritious food crop. Alfalfa sends it's roots deep into the soil.
Soil or Waste Stacks. A soil or waste stack (normally just called a stack) is a drainage pipe that passes through at least one story(floor to ceiling) as a drain pipe, this also includes any horizontal offsets. Every soil or waste stack will terminate in a stack vent that leads to outside air or a vent header.
3 Single stack system. This system is having a single pipe for soil, waste and vent without any separate ventilation pipe. It uses only one pipe, which carries night soil as well as sullage and the same pipe is extended up to 2 m above roof level with a cowl to act as vent pipe for removal of gases.