Every spring for the past three years I've had a tiny little wren build herself a nest in the framework of the door on my adult coop. I've long since given up trying to discourage her. By the time I discover her nest she usually has eggs in it and I won't just casually throw out the eggs that she's worked so hard for. The only way to definitely keep her from making her nest there would be to lock the pop door on the coop. I can't do that because the hens need to have access to their nestboxes; so the wren stays. I've settled for spraying her nest down with the poultry protector/mite spray each spring. Today I happened to notice her nest that's up against the styrofoam insulation on the inside of the door. Most of the insulation behind her nest is gone; a gap approximately the size of a tea saucer. Mrs. Wren's nest looks kinda cozy lined with all that insulation. At least she's using it towards a goal. If the chickens could reach it, they'd just eat it.