I have 8 plastic gourds for purple martins to nest in. These gourds are on a pipe and pulley arrangement so they can be lowered for cleaning. They have a large lid you remove so you can remove sparrow and starling (undesirable) nests. This year the starlings and sparrows have taken over my gourds, no martins nesting in them. I lowered it today to clean out their nests. Got to about the fourth one and stuck my hand into a very large wasps nest. About 6 bites on my hand and one on my chest. Glad I'm not allergic to them. Was a non poisonous snake was in one of my martin houses years ago when I lowered it.

If you use the real gourds (not plastic) be sure to soak them in bleach before using.They'll last longer as well as being free of any fungus,etc.