Every year now for four years a phoebe has built her nest on the side porch fan blade. She makes a bit of a mess, and it makes porch sitting difficult, but watching her build, and then sitting on her eggs, and then the anticipation of the hatchlings - well, it is worth it. I see them right out of my kitchen windows. When the babies get bigger and out of the nest they hang out on the other blades for a few days...and then poof, they are gone.
I take down the nest, scrub the blades and the porch ceiling and floor and all is clean again until ....now! Welcome back Mrs. Pheobe.