Hi HowieDawn

What cute "grandkids" you have They are looking really good and nice and plump, just as they should. Good job to you and to the parent birds.

As for the nesting box, yeah you should be cleaning it once a week or so. The easiest way for me was to first put the chicks in a temperary, warm nest and then get a good sized paint scraper and scrape the sides and bottom then toss out the dirty and refill it with fresh nesting material. Pine shavings are what I used but cotton balls sound fine too.

Have fun with the gang They are adorable, I just love baby birds!