Beware of leaving your clothes hanging on the line too long
Wrens are notorious for building nests anywhere, anytime. We believe it is compulsive behavior on their part. The other day I noticed movement behind a fitted sheet I had hung to dry. They were bringing leaves and putting them in the elastic pocket formed in the edge of the sheet. We have found nests in plastic bags, under towels draped over chairs, in large pots on the patio, in the sleeve of a jacket. This one was in the pocket of some shorts that were left on the line over night.