Today I stuck the GoPro in and all I could see was a Leg sticking straight up. My stomach dropped. 2 of the babies were dead in the nest and only one baby was left. It looked healthy but ants had eaten some of his brothers and sisters. Here's to you last little bluebird.
I put ant killer around the base and did not dare pull the nest with the baby in it. I will do some research and see if I need to pull the nest to clean out under it.