 The good news is there's really not much to fret about. According to Paul Stamets, 95% of LBMs are not deadly toxic. Now, if you eat a mushroom, you're going to have diarrhea. I mean, because mushrooms are made of the same thing that crab shells are made of. They're made of chitin, and we can't digest it. But most of them, they're not harmful. And typically, those little brown mushrooms are just the tip of the iceberg for the microbial life that is in your soil that is helping your lawn