After going thru our new old Shadow Cruiser TC, I found old wasp nests in the roof sewer vent pipes while resealing the roof, removed them and got to thinking of a fix for a repeat. At our Walmart, as well as Ace Hardware, I found some wire sink drain strainers in various sizes and one size fits exactly on top of the black pipe. Added some adhesive to insure they stay in place and roared the caps. Problem solved. They're really inexpensive. I use them in my sink to prevent any tiny particles from getting in the grey water holding tank as well.
2004 Chevy 3500 Duramax all stock
1990 950 Shadow Cruiser Hard side multiple add-ons
Ancient Valco 10'x5' John boat
2011 Toyota FJ Cruiser Trail Team
One-eyed Trail Horse and one horse trailer
Rocky, Annie, Muffie traveling Fur Babies