I'd be a little concerned about the poop. Is it biodegrading into soil, or just drying out and sitting around? Otherwise, sounds like a pretty good spot for some kind of useful fungi. My only reference for this is Mycelium Running
(Paul Stamets), which gives clear basic instructions for a variety of ways to cultivate a variety of mushrooms. (and page after page of fascinating, inspiring, mind-blowing knowledge about what these magical allies can do) And I just loaned it out the other day, so I can't look into it right now!
A lot of mushrooms grow on fresh dead logs (i.e., that haven't already been colonized by wild mycelium). Some grow on straw, compost, wood chips. It's a change in the climate (heat, rain, sunlight) that can start the hidden mycelia fruiting into those beautiful mushrooms.
For indoor cultivation, you can buy a kit (fungi.com
sell some), and maybe you can find some that will find your space suitable.