While cleaning my basement I found an alarming pile of what I assume is poop, though I would be delighted to discover it was something else.
That's 3/4" electrical conduit, for scale. The individual bits are about 1/8" in diameter and very long, in some cases over an inch long. Does anybody recognize this stuff either as a biological product or the result of some erosive process in my concrete floor? There are no signs of mischief in the ceiling above.