Awww. I just love the little wrens. I had one nest in a tiny house this summer that was supposed to be a decorative house, not a real one. After the babies hatched, we had a terrible storm and the house came down. We were camping so didn't know for a couple of days. The babies died. I was sad.
Your pictures are adorable. P D Eastman wrote a children's book called, My Nest is Best. The story goes that momma bird wanted a new house and poppa went all over trying a mailbox, a work boot, and I don't remember all the possibilities. Momma tried them all and found problems with each one. The eventually decided that their first home was best.