This little bugger is in my finished garage ceiling. It has a vaulted roof to the space above the ceiling sheet rock is about 6 inches and insulated. There are two small holes just along the ridge beam rafter, where the sheetrock and wood bean join.

Out of these two 1/8 inch holes comes small amounts of debris. Maybe about a teaspoon of dark "dust" over a week.

Is it it a trash door for a spider? For a mouse?

#1 of several suspects is carpenter ant. Debris is 'frass' & would have ant body parts - check w/ mag glass. Contact me f/ N/C tips on control.