Yes, that is what happens when you have dampness plus an organic substrate such as hay.
I would suggest quit using the hay, and do what you reasonably can to keep water out of the run better. See my 'fixing a muddy run' page (link in .sig below) for a buncha suggestsions -- it should probably be called "fixing a muddy OR STINKY run" LOL
Also note that the more chickens you have in the less space, the worse the problem is.
Good luck, have fun,
Pat
I would suggest quit using the hay, and do what you reasonably can to keep water out of the run better. See my 'fixing a muddy run' page (link in .sig below) for a buncha suggestsions -- it should probably be called "fixing a muddy OR STINKY run" LOL
Also note that the more chickens you have in the less space, the worse the problem is.
Good luck, have fun,
Pat