From what I can find its used for pH levels in soil. I'm not an expert either. I'm sure they would eat it has they need to normally. Sorry I wasn't much help.
This is our first year owning chickens. We haven't had a problem all spring/summer. Now I have moved them to the summer kitchen for the winter. Don't really have to worry about predators in there. Best you really can do is secure everything to the best of your ability. Good luck.
I live in north eastern PA. We have been going through a bunch of rain. My run started as grass, but we all know how long lasts. Ha. I was using grass clippings and and such. But with all this rain the run as turned into a gross mud run. I just added sand at least what I had in the garage. Means...
I live in Pennsylvania. Using pine shavings as base and straw on top of it. Coop doesn't smell. The straw defiantly helps keep the coop insulted. I do use dry herbs thru out. My girls roost with no problem. Hope it helps.