Very soon I hope to have 5new born. The cock bird is very protective of the nest box already. How long after the last chick hatches, will it be safe to start cleaning the nest box.2 years ago I left it until 4-5 weeks because the same cock bird gets very aggressive and protective and I got MITE, WHICH PROVED VERY DIFFICULT TO GET RID OF. Fortunately all was well in the end but a lot of hard work and worry for the new borns health.looking for prevention not cure. PLEASE HELP. PS, What is the best lining.