If you have outlet boxes on the outside of your home that are filled with bugs, it's likely because you don't have a "bug plug" covering the holes that lead into the outlet box. These holes allow cords to pass into the weatherproof box, while the cover is closed, but also allow insects to get in if they're not covered.

This "bug plug" as it's called, fits into the Extra-Duty 3R-style weatherproof outlet boxes and fills the hole so that bugs cannot get into the outlet box. This "bug plug" was modeled from another that I had on a separate exterior weatherproof box and should be a direct replacement for the aforementioned 3R-style outlet boxes.

To install, simply hold the "bug plug" by the sides with the top side (side with the two "prongs") facing up and slide into the void at the front/back of the weatherproof outlet box. The two top "prongs" should be above the side of the outlet box and the single "prong" should be below with the main portion of the "bug plug" filling the void. Simply remove in order to open the void again to run cords to the exterior outlet.