I have five Buff Orpingtons, that are 3 1/2 months old. Growing quickly, getting big, healthy. We are raising them organically, without antibiotics, organic feed, etc. I let them free range for most of the day without difficulty. The other day I saw them converged on something that was holding their interest for a while, not like bugs that they like to chase. As I approached, I observed them eating a large "toadstool" type of fungus. I shooed them away and destroyed the fungus. That was 5 days ago. They are still alive, and I don't think they had any hallucinations that day. Do chickens know which fungus they can eat, which ones will harm them?