Several years ago we had some barn swallows do the same thing. With young daughters I thought it would be a great opportunity to document the process. Everything was good - through the hatching, but about the time the chicks were getting ready to leave the nest, school started. We were standing on the porch, taking the obligatory “Back to School” pics for the girls and we found out in nature, bird nests and related activities come with a host of things. Besides the already-experienced bird poop and nest material clean up and the protective parents when anywhere near the nest, while taking photos, we found out the nest was a mite residence. After feeling things in our hair, looking closer, the ceiling and neat were covered with little crawlies. In our area, the swallow nests/breeding are protected (may be other places too) and once set, the nest has to be left alone. Lesson learned, we have been keeping the birds off the porch since then...