What is the simplest way to disinfect bird houses after I clean them each fall?
The best thing to do is use a 10% bleach solution (1 part bleach - 9 parts water) to thoroughly disinfect the house. After you do this, you can let it air for 24 hours and then either store it and put in back in use. The bleach will kill viruses, bacteria and anything else. Be sure to wear gloves.