I looked up in my living room this morning and noticed a line of small brown spots, right along the precise middle of a barely visible tape joint at the 8' point. Upon closer inspection, it turns out these are about 10-12 holes, the largest of which is about half the size of a pencil eraser, with some brown crusty material covering up a good bit of each of the holes. The room is the only room on the middle level of a tri-level house and the wall with the holes is on one side of a partial divider between the living room and the entry foyer. The ceiling is sloped as is the roof section above it. I assume that the top of the stud wall is covered with a plate of some sort that will prevent me from looking down into the wall cavity to scope things out, even assuming the area is accessible.

At this point, I assume I have some type of insect activity but I have no idea what type, and more importantly, what to do about it. The damage is negligible so far and confined (some spackle, primer and paint in a roughly 40 sf area will take care of things) but I sure want to stop the little buggers in their tracks. Any guesses what might be going on? Any suggestions for treatment? Is this (exterminating) a DYI project or do I need to call in the pros? I am reluctant to spray anything in the existing holes for fear of damaging the drywall. TIA, Tony