Just North of Wisconsin's Lake Superior shoreline, we've got Northern Ontario, land of the big, steroid sized black flies. The saying goes that if 6 of them get on you, you can fly east for free! Man are they big!
One summer, the mayflies were so bad on the Hwy 33 Bridge going over the Wisconsin River that cars were sliding like it was winter, they had to bring the plow trucks to get all the mayflies off the road!
The whole thing is a duct, whatever comes in... black flies, skitters, wind. As for the engine hoist ---- None Required (this year anyway)