New cowl plugs installed, made by Bruce’s…same as the canopy cover. The first set from MAC’s were the “wrong ones”, made to fit the later model Cessna 15o’s..the “L”, “M” models. Those have the fiberglass cowl nose which encircles the propeller hub. Earlier Cessna’s such as N5655G, a 1970 “K”, have the “open” style metal cowl nose. Well, the birds sure liked the wrong plugs and they made a nest (twice!) in the engine compartment. Seems the “gap” (with the incorrect plugs) allowed a “private entrance” behind the propeller spinner, where the birds felt nice and secure. No more! Also, there are blue nylon “scrub pads” in the air intakes in the leading edge of the wing. That is to keep the wasps out. They seem to love air intakes.