I recently was very fortunate to have an Anna’s hummingbird build a nest 15’ up in an oak tree in my backyard. It was about eye level from my 2nd story home office, so I was able to watch the babies from egg to fledge.
The two fledgling have only been out of the nest for a few minutes and Mom is already cleaning it for her next brood. She very carefully removes the old feathers one by one, sometimes flying off to release a feather into the open air.