Peat moss comes from peat bogs. It takes THOUSANDS of YEARS to form. It is also a delicately balanced ecosystem. Compost on the other hand takes WEEKS to form. Freedom of choice is fine so long as you do no harm. Destroying ecosystems to use an irreplacable substance when there are much better substitutes is wrong. Did I mention inhaling the dust can cause permanent lung damage? If your chickens are digging in it, and scratching it up in their coops and runs, they are breathing in the dust.