Why does this insect/other debris keep accumulating in this spot in my basement?

Photos in the link at the end. Red is problem wall, blue is where I sealed the rim joists and the foundation floor edges.

This is in my completely underground basement's laundry room. I can't tell what this debris is besides the obvious shitload of insect carcasses. I highly doubt mice because my cat loves to kill and shows no interest in any particular area. The other side of the red circled area butts up against my garage and where the debris must be falling from. This buildup doesn't happen anywhere else in the laundry room, including the other walls that face outside.

Any ideas on why this is happening? I'm thinking this is some sort of bug superhighway and I need to use silicone to seal between the wood and concrete. Also the fiberglass insulation seems like it could be done better, probably will replace it with foam board.

Pics: https://imgur.com/a/NcL6bsg