Should you clean bird houses?
In most cases, yes. Many bird conservation groups recommend removing old nests from nest boxes once the birds are done. Old nesting material can hold parasites such as mites and lice, and a clean box may be more appealing to the next occupant. Some species will even build over an old nest, which can leave later nests closer to the entrance and easier for predators to reach.
The science is not completely settled. Research reviewed by NestWatch, the Cornell Lab of Ornithology project, suggests that cleaning has mixed effects on parasite levels, and not every species cares. Cavity-nesting birds like chickadees and bluebirds often use a box again whether or not it was cleaned. Still, removing the old nest and checking the box is widely considered good practice.
When to clean
The key rule is to clean only when a box is no longer in use.
- After each brood is finished. Species that raise more than one brood a season, such as bluebirds, may benefit from a quick clean-out between broods. Wait until the young have fledged.
- Late winter or early spring. If you did not clean in fall, do a thorough job before nesting begins, usually by late winter. In answer to the common question about bluebirds, many guides suggest the box be ready by late winter or early spring, though timing depends on your climate.
- Fall. Cleaning in fall is common once nesting is clearly over, but some birds use boxes for winter roosting, so many people wait until late winter.
A note about active nests
In the United States, native birds, their nests, and eggs are protected under the Migratory Bird Treaty Act. Do not remove a nest that contains eggs or young. If you are unsure whether a nest is active, watch from a distance for several days. House Sparrow and European Starling nests are treated differently, but rules vary, so check local guidance.
Step-by-step cleaning
- Confirm that the box is empty and that no adult birds are still using it.
- Put on gloves and a dust mask. Old nests can carry dust and mold, and can contain insects.
- Open the box and scrape out the nest and droppings into a bag. Dispose of it away from the box.
- Scrub the interior with a stiff brush and warm water. For extra disinfection, NestWatch and other guides suggest wiping with a diluted bleach solution of roughly one part bleach to ten parts water.
- Rinse well and leave the box open in the sun to dry completely.
- Check for damage. Look at the roof, the drainage holes, the ventilation gaps, and the hinges, and repair what you find.
- Wash your hands afterward.
What to use and what to avoid
Can you use Dawn dish soap? A little mild dish soap in water is sometimes used to scrub, but it must be rinsed thoroughly and the box dried completely. Many people prefer the diluted bleach approach followed by a thorough rinse. Whichever you choose:
- Avoid strong scented cleaners, pesticides and aerosol sprays inside the box.
- Do not use chemicals that leave residue.
- Let everything dry fully before closing the box and putting it back out.
Special cases
Bluebird boxes. Monitor and clean between broods. See our bluebird nesting box plans for designs with side or front openings that make this easy.
Wasps and other insects. If wasps have built in the box, wait until cold weather, when they are inactive, then remove the nest carefully.
Gourds. Natural gourds degrade when soaked. Brush out the nest and let it dry rather than soaking. See gourd birdhouses.
Boxes that cannot be opened. If a box has no door, it is harder to clean, and you may want to replace it with one that opens. Check that any replacement uses a suitable hole size.
Frequently asked questions
What do you use to clean a birdhouse? A stiff brush, warm water, and, if you wish, a dilute bleach solution, followed by a thorough rinse and drying.
Are you supposed to clean bird houses? Most conservation groups recommend it, as long as the box is not in active use.
How often? At least once a year, and between broods for species that nest more than once.