How to Attract Bats to a Bat House

How to attract bats to a bat house comes down to warmth, location, and patience. Put up a tall, multi-chambered house before bats return in spring. Mount it on a building wall or a pole rather than a tree, with at least 12 feet of open air below it. Give it most of a day’s sun, and paint it a shade that matches your summer heat. A site within about a quarter mile of a stream, pond, or lake helps. Then wait: a new house can sit empty for one season or several, and some well-placed houses never fill.

Below, each step is tied to the state wildlife agency, federal, or bat conservation guidance it comes from. Where those sources give different numbers, we show the range and say which end we would start from. The goal is a house that bats can find and will choose to stay in.

Never touch a bat with bare hands, and teach everyone in your household to leave grounded bats alone. The CDC lists bats among the animals most often found with rabies in the U.S. If anyone may have had contact with a bat, or was bitten or scratched, get medical help and talk to your local health department. For an injured or grounded bat, contact a licensed wildlife rehabilitator or your state wildlife agency. This guide is not medical or legal advice.

How to Attract Bats to a Bat House: The Checklist

• Sun: at least 6 to 8 hours of direct sun a day, with morning sun favored in the hottest climates.
• Color: dark where summers are mild, light where they are very hot, matched to your average July high.
• Mounting: a wood, stone, or brick wall or a sturdy pole. Not a tree, and not a metal building.
• Height and clearance: at least 12 feet of open drop below the entrance, away from branches and bright night lights.
• Water: ideally within a quarter mile of a stream, pond, lake, or wetland.
• Timing: up before local bats come back in spring.
• Design: tall, several narrow chambers, roughened inside surfaces.
• No shortcuts: no lures, no relocated bats, and at least two full seasons before you give up on a spot.

Why Warmth Matters Most

In summer, female bats gather in maternity colonies to give birth and raise their pups, while males roost elsewhere, according to Iowa DNR, which notes that a bat house in the right location gives these colonies a place to form. Pups are born hairless and need high temperatures to stay warm while their mothers hunt, per the Florida Fish and Wildlife Conservation Commission.

That is why temperature drives almost every other choice. A USDA Natural Resources Conservation Service technical note from New Mexico calls proper roost temperature possibly the single most important factor for a successful bat house. It puts the ideal summer interior at 80°F to 100°F, warm and as stable as possible, and says exterior color, compass direction, hours of sun, and how tightly the house is built all affect it.

Which bats are you likely to get? Little brown and big brown bats are the species most likely to use bat houses, according to Iowa DNR and a USDA Forest Service flyer from Hoosier National Forest. Delaware’s Division of Fish and Wildlife adds the tri-colored bat. For New Mexico, the NRCS note also lists the Mexican free-tailed bat among species that roost in bat houses.

Give the House Enough Sun

Every source we read asks for a sunny spot, but the number of hours varies. Bat Conservation International (BCI) says bats prefer early morning sun and at least 7 hours of sun, and notes that a house on an east-facing wall gets morning rather than afternoon sun, which matters in warm southern climates. The NRCS note recommends at least six hours of direct daily sun and says full, all-day sun often works in all but the hottest climates; with only part-day sun available, morning sun is preferable. Virginia’s Department of Wildlife Resources asks for 8 hours or more, which generally means a southern exposure.

Our reading: start at the higher end. In most of the country, a south- or southeast-facing spot with 7 to 8 or more hours of direct sun meets the sun-hour figure of every source in the table. Where summer highs regularly pass 100°F, favor morning sun and a lighter color (next section) so the house does not get too hot by afternoon.

In cold northern areas the problem runs the other way. Alaska Department of Fish and Game advice suggests the warmest exposures you have, and putting up two houses that face different directions so bats can pick the temperature they want. The NRCS note makes a similar point for poles: two multi-chambered houses mounted back to back, one facing north and one facing south, is described as ideal.

Paint for Your Summer Heat

According to the NRCS note, bat houses are far more successful at attracting bats when they are painted or stained, because color controls how much solar heat the box absorbs. A painted box warms a few degrees faster in the morning, which the note calls critical in spring, and averages about five degrees warmer at midday. Use exterior-quality, water-based stain or latex paint, choose a flat finish for the best heat absorption, apply at least three coats, and do not use oil-based products. Do not paint the inside: paint fills the grooves bats grip, so the note suggests a dark water-based stain if you want to protect interior wood.

The note matches shade to the average July daily high where you live:

Two adjustments apply. Go a step darker if the spot gets less sun than recommended, as the note advises. And remember the shade matters more than the exact color, so a dark brown can stand in for black in a cool climate. BCI gives the same general rule: a light shade in hot climates, a darker one where the house needs to hold heat. Virginia DWR mentions black roofing paper on the upper section as an alternative to dark paint. Plan to touch up the finish: the NRCS note says to check the house once a year for gaps or cracks from deteriorating caulk or warped wood, and to caulk or repaint during the winter months, when bats are not present.

Mount It Where Bats Can Find It

BCI ranks the options plainly: poles are better than trees, and the wall of a house is better still, because a pole-mounted house is not as well insulated as one built against a wall. It prefers wood, stone, or brick buildings and says bats will rarely use a bat house on a metal building, a point the NRCS note repeats. Trees cause three problems that Iowa DNR names: too much shade, branches that block the drop into flight, and easier access for predators. Virginia DWR cites the lack of sun.

Two sources are less strict. The Alaska advice says trees can be good options in parts of Alaska, and the Hoosier National Forest flyer lists a tree among possible mounts. Given that most agencies advise against trees, we would treat one as a last resort.

Height is about room to fly. Bats drop from the house to begin flight, BCI explains, so it calls for at least 12 feet of open space under the exits and says higher is better. The NRCS note adds three placement rules worth following anywhere: keep the house at least 20 feet from the nearest tree branches, wires, or perches for aerial predators; keep it away from yard and security lights, and never mount it on a light pole; and avoid hanging it directly over windows, doors, or walkways, since droppings fall from the open bottom.

Water and Insects Nearby

Virginia DWR says research has found maternity sites are usually within a quarter mile of a natural water source. The NRCS note says most bats choose roosts within a quarter mile of slow-moving water, preferably a stream, lake, or wetland that lasts through summer, and that the best sites mix farmland, natural vegetation, woods, and water, which produce different insects through the night and the season. Alaska’s advice points to the same kind of landscape: watercourses, ponds, lakes, and open meadows next to woodland.

You cannot add a lake to a suburban lot, and you do not need to know where the water is. Virginia DWR suggests trying the house anyway, since the bats may know of a water source you do not. What you can control is food. The NRCS note warns that bats may not be able to live in areas of heavy pesticide use because the insects they eat are scarce, and it suggests plants that support a variety of insects. Cutting back on yard insecticides and keeping insect-friendly plants is the part of the habitat you control.

Install Before Bats Come Back in Spring

A bat house can go up any time, but it is more likely to be used during its first summer if it is installed before bats return in spring, per the NRCS note. Delaware’s guidance says early spring. In Virginia, bats generally leave their winter roosts for summer sites in April, and the state’s wildlife agency says having the box up before then gives wandering bats more chances to find it. Your state wildlife agency can tell you when bats become active where you live.

Missed the window? Virginia DWR says to put the house up anyway in your best spot, and if it is not used the first year, give it a second chance the following year. Do any repairs, recaulking, repainting, or wasp-nest removal in winter, after the bats have left; BCI says never to disturb a bat house while it is occupied.

What the House Itself Needs

Placement cannot rescue a poorly built house. In brief, the published guidance asks for:

• Size and chambers. The NRCS note sets a minimum of 24 inches tall and 14 inches wide, with taller and wider being better. BCI says recommendations now favor four chambers over two, and tall, multi-chambered houses have the greatest occupancy rates.
• Narrow crevices. Chambers spaced 3/4 to 1 inch apart, with 3/4 inch best for most North American bats, per NRCS. Gaps wider than 1 inch invite wasps.
• Grip. Rough-sawn wood or horizontal grooves on the inside walls and on a landing area that extends below the entrance (at least 3 inches, with 6 inches best, per NRCS). Avoid metal mesh, hardware cloth, or window screen, which the note says can injure bats.
• Materials. Exterior-grade plywood, cedar, or redwood, galvanized screws, and caulked seams, per Virginia DWR. Never pressure-treated wood.
• Venting in hot regions. Where July highs average 85°F or more, the NRCS note calls for a front ventilation slot.

Building one yourself is a manageable project, but a bat house differs from a birdhouse in ways that matter: it usually has an open bottom, narrow vertical chambers, and roughened walls instead of a floor and a round entrance hole. If you buy one, check it against the list above. BCI says it no longer certifies purchased bat houses and asks buyers to apply its guidelines to pre-made houses and kits, so an old certification label is not a substitute for checking the dimensions.

Skip the Lures and Never Move Bats In by Hand

It is tempting to speed things up with guano or a scent. The sources agree it does not work. BCI says lures such as guano, scents, or sounds do not attract bats to a house. The NRCS note says existing evidence strongly suggests lures and attractants will not draw bats in, and that bats find new roosts on their own while foraging at night. The Alaska advice puts it simply: you cannot bait them in.

BCI also says not to catch bats to put into a house. Beyond the rabies concern above, wild bats are protected in many places: Florida’s wildlife commission notes that it is illegal to kill bats in that state. Repellents and poisons have no place around a bat house.

How Long It Takes, and How to Tell Bats Have Moved In

The sources disagree on timing

Expect a wait, and do not trust a single number. The Hoosier National Forest flyer says bats often take 2 years to occupy a new house and only about 15 percent are occupied at any time. BCI itself says it has seen successful houses take as many as five years before bats moved in, and that bats may never use some houses.

The cautious plan is to give a house two full summers. If it is still empty, both the NRCS note and the Alaska advice suggest moving or modifying it. Before you move it, check the likely causes in order: too little sun, a shade too light for your climate, branches or wires too close, or a bright light nearby.

Signs that bats are using it

• Droppings below. The NRCS note explains that most bat houses have open bottoms, so guano ends up on the ground underneath instead of building up inside. Fresh droppings under the house are an easy sign of use.
• The dusk count. Sit where you can see the entrance against the sky around sunset and count bats as they drop out. Delaware’s guidance says you may have more luck counting bats as they emerge at dusk.
• A brief look, rarely. The NRCS note advises checking on the house at least once a month for problems such as predators, overheating, or wood deterioration. Delaware says an established colony tolerates people as long as the house or post is not disturbed and direct light stays on the bats for no more than 10 seconds.

In Florida, the state wildlife commission invites people to count bats emerging from bat houses and report the numbers to the Florida Bat Working Group, a simple way to make your evening count useful.

Handling the guano

Virginia DWR says droppings can stay on the ground under the house until the bats leave in fall, then be shoveled up and added to compost. The NRCS note is more cautious about handling: it advises wearing gloves and a HEPA-filtered face mask when handling a bat house or guano, or when disturbing the soil below one, and washing those clothes right away. We would follow the more cautious advice.

If Bats Already Live in Your Attic or Walls

A bat house is often put up for bats being removed from a building. Delaware’s guidance says to install the house 2 to 6 weeks before the bats are excluded, and Florida’s commission suggests placing it in the bats’ exit flight path, while noting that bats are unlikely to switch to a bat house until after an exclusion.

Exclusion itself is regulated, and the allowed dates differ by state. New Jersey’s Division of Fish and Wildlife says it cannot be done in May, June, or July. In North Carolina, licensed wildlife control agents may not perform bat evictions or exclusions from May 1 through July 31, outside of approved exceptions. Florida makes it illegal to install exclusion devices without a permit from April 16 to August 14. Contact your state wildlife agency before any work on a building with bats; this guide does not cover exclusion methods. For a single bat indoors, the CDC advises contacting animal control or your health department so the bat can be captured and checked for rabies.

Bat House FAQ

How long does it take bats to move into a bat house?

Anywhere from one summer to several years, and sometimes never. BCI has seen successful houses take as many as five years. Give a well-placed house at least two full summers before moving or changing it.

Do the bats in a bat house eat a lot of mosquitoes?

Mosquitoes are on the menu, but they are not the main item for the bats most likely to move in. The NRCS note describes little brown bats as eating mostly midges, with gnats, craneflies, beetles, mosquitoes, and other insects, and big brown bats as feeding mainly on beetles while also taking flies and mosquitoes. Some state agencies describe bats as eating large numbers of mosquitoes, but none of the sources we read measured how much a single bat house reduces mosquitoes in a yard. Treat fewer bites as a possible bonus, not the reason to put one up.

Can I use bat guano or a scent to attract bats faster?

No. BCI says guano, scents, and sounds do not attract bats to a house, and the NRCS note reaches the same conclusion. Sun, color, height, and a nearby water source do far more.

What should I do if I find a bat on the ground under the bat house?

Do not pick it up. BCI reminds people it is never safe to touch bats found on the ground. Virginia DWR notes that a mother bat will generally find a fallen pup and return it to the box. If the bat seems injured or is still there the next day, call a licensed wildlife rehabilitator or your state wildlife agency. If anyone touched it, get medical help and contact your local health department, as the CDC advises.

Final Thoughts

Attracting bats is mostly about heat and access. Choose a sunny wall or pole over a tree, paint the house for your July highs, keep the drop below it open and dark, and have it up before spring. Then count at dusk, keep your hands off, and give it two summers before you move it. Every number in this guide links back to the agency or organization that published it; see How We Review for how we research guides. More nest box and bat house guides are collected in our Birdhouses section.

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