Bluebirds do not actually build their own nests, but instead take over nests that have been abandoned by other birds. However, if you want to attract bluebirds to bluebird houses in your yard, you will, surprisingly, have to do a little bit of maintenance in order to make these houses attractive to your brightly colored guests.
Remove the bird box from its mount. It will be easier to get the bird box as clean as possible if you can access it from all angles. If possible, take the box down before you start cleaning.
Put on your rubber gloves. Bluebird houses should be cleaned out at the start of each season and also after each bluebird brood has flown the nest. Protect yourself from avian pathogens that may grow in the waste in the box by wearing rubber gloves throughout this procedure.
Mix your cleaning solution. Mix a solution of 10 percent bleach and 90 percent warm water. You can make it in the bucket. First add 1 cup of bleach to the gallon bucket. Then, fill the bucket about three-quarters of the way full. This will make a roughly 10 percent bleach solution.
Pull all the debris and nesting materials out of the bluebird box. Place it in the garbage bag, since leaving it lying on the ground can attract predators. Make sure that the box is as clean and as clear as possible before you start scrubbing.
Scrape any caked on residue off of the interior of the box with the plastic scraper. Be gentle and always scrape away from yourself to avoid injury.
Scrub out the box. Dip the scrub brush into the mix of bleach and water and get to work. Scrub the entire box out with the cleaning solution. Once the box is completely clear of of dirt, grime and debris you can let it dry for about 48 hours before returning it to its original location.