Oldwolf
No use to you I'm afraid, but we had a rarely used peg bag hanging on the washing line, and last year we noticed much coming and going of our resident robin. On checking the peg bag, we discovered her nest and four eggs! Plenty of more suitable local and natural places including several specially designed robin nestboxes to rear her brood, but she chose to use it anyway. After fledging, there was one "dud" egg remaining in the nest, so we assume that three chicks were successfully reared.
Yes, but Mrs Robin could be certain she and her babies were safe from cats. I have yet to see the cat tight-rope walking on my clothes-line!
And her babies may even have been safe from the magpies and crows there.
Smart bird!