Bed Bug Nest and Eggs
This is another picture of the same ledge at the other end.
You have a Canadian 2 dollar coin placed in this nesting spot for comparison. The shiny white and somewhat translucent eggs with a hole on one end are clearly visible. The shiny black extruding dots are their excrements dried up over time.
You see some lighter color and much smaller Bed Bugs that are the babies. They are about 10 times smaller in size than the full adults.