Ryles’ PML frass sample

Ryles Richards brought in a sample of a very tiny, mostly pelleted material from a home in Groveland. A small pile of this material has been accumulating slowly at one spot in the house, next to a baseboard. The pellets are extremely small. In the photos that have a ruler, for size estimation, that is the millimeter scale, so the pellets are approximately 1/10 of a millimeter wide.

Examination of the material shows that some have a hair-like structure sticking out of them. We have included a number of pictures of the round pellets that have a hair-like structure.

There is an occasional, more typical-looking, probable fecal pellet.

I presume this is frass from some kind of beetle living in that one spot. But what?