Nest box requirements vary by species, but several characteristics for birdhouses are universal. Follow these guidelines for providing the safest home.
Welcome Feathered Families With Unique Birdhouses
Updated on Apr. 28, 2025
Being a bird landlord and managing a nest box is an exciting way to help your feathered neighbors, but it comes with great responsibility. According to Dan Sparks, who has been involved with Indiana’s Brown County Bluebird Club for nearly 30 years, it is important that birdhouses provide good ventilation without compromising protection from the elements. How to care for it is another essential. “The box should easily open from the side, front or top for cleaning and monitoring,” Dan says.
To boost your chance of attracting nesting birds, follow these basic birdhouse guidelines. You can actually attract different species to unique nesting boxes based on the size of the entrance hole, the location, and more.
Here are more things to consider.
Say No to Fancy Birdhouses
Fancy or extra-elaborate birdhouses are nice to look at, but they are often not functional. When these pretty abodes are made of metal, the temperatures may get unsafe inside the box. Painting wooden boxes with nontoxic paint on the exterior months in advance can allow any fumes to dissipate, and some nest box monitors choose light colors of paint to help keep internal temperatures down. But the Cornell Lab of Ornithology’s NestWatch website recommends erring on the side of caution and sticking to untreated and unpainted wooden boxes.
However, if you want to display a more decorative birdhouse that isn’t going to be functional, simply cover the hole with a wooden block or a copper or plexiglass plate. Blocking access to such birdhouses before placing them outside will keep birds safe while also bringing a bit of whimsy to your space.
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Offer a Good Roof and Air Conditioning
Birdhouses with sloped overhanging roofs are preferable to help prevent rain from getting inside, according to Dan. Channels or grooves cut under the edges of the roof are added features that function as mini rain gutters. Drainage holes and recessed floors prevent dampness from accumulating on the bottom of the box. Ventilation holes should be near the top of the box to allow hot air to escape.
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Location, Location, Location
Put out birdhouses early in the season—by February in the South and mid-March in the North. Bluebirds and swallows prefer mounted boxes in open areas. Wrens and chickadees are comfortable with hanging houses closer to cover or in the woods. It’s tempting to put nest boxes near feeders to create a bed-and-breakfast of sorts, but it’s best to keep them separate. The bustle of activity around feeding stations isn’t conducive for raising babies—and it might attract predators. Most species like to nest in isolation, but a few birds, including purple martins, are communal nesters and require special boxes with multiple chambers.
Find out how long baby birds stay in the nest and more nest facts.
Evict Squatters
In North America, nonnative European starlings and house sparrows are unwelcome squatters. Smaller entrance holes keep starlings out in most cases, but both species can be problematic in boxes with larger entrance holes and in communal houses like those for purple martins. Dan suggests removing house sparrow nests, although he notes that it can take multiple attempts because house sparrows are persistent. NestWatch and the North American Bluebird Society websites both note that humanely euthanizing house sparrows and European starlings is another management method, since these two species, including their nests, are not protected under the Migratory Bird Treaty Act.
Welcome nesting wrens to a wren birdhouse.
Keep Out Unwanted Guests
Although nest predation is a natural process, you should attempt to minimize it in your nest boxes. Snakes, raccoons, squirrels and chipmunks are just a few of the potential predators to deter. Baffles are effective at preventing critters from having access to a nest box. Hole extenders or predator guards can be attached to boxes to make it more difficult for predators to reach into a nest box and grab the eggs or nestlings. Perches aren’t necessary for cavity nesters, so they should be removed from boxes. This helps minimize access for unwanted house guests too.
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Monitor Regularly
It’s important to keep track of nesting progress. “Remove any attempts of wasps to build a nest, and check for ants and blowflies,” Dan says. Monitoring is also helpful to “make sure eggs are in the nest cup and are being rotated,” he says. According to NestWatch, nest boxes should be monitored at least weekly, but not more than every three to four days, which is the right balance between overly disturbing the nest and neglecting it. And it’s best to approach a nest after the female has left the box on her own.
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Clean Birdhouses Often
Having a nest box that opens easily is essential. Dan says that “it is best to remove the nest at the completion of each nesting attempt.” Depending on the species, birds raise up to three broods per nesting season, so cleaning a nest box between nesting attempts is important “for sanitary reasons and to make it farther for a predator to reach to grasp an egg or nestling,” Dan says. Cleaning out the boxes helps freshen them for the next nest and protects future nestlings from diseases and parasites too.
Tree Swallow Dimensions
- 5″ x 5″ x 8″ h.
- Hole 1 ³/₈” centered 6″ above floor
- Placement 5 to 8′ high in the open; 50-100% sun
House Wren Dimensions
- 4″ x 4″ x 8″ h. or 4″ x 6″ base
- Hole 1″ centered 6″ above floor
- Placement 5 to 10′ high on a post or hung in tree
Pygmy Nuthatch Dimensions
- 5¹/₂” x 5¹/₂” x 8″ h.
- Hole 1″ centered 7″ above floor
- Placement 3 to 25′ high in open areas of pine forests
American Kestrel Dimensions
- 10″ x 10″ x 24″ h.
- Hole 4″x 3″ elliptical 20″ above floor
- Placement 12-40′ high on a post or tree trunk
Want to DIY? Learn how to make your own a purple martin gourd house.
