In the right conditions, a quality constructed bat house installed where it receives plenty of sunshine within the proximity of surface water in a species' range, bats will discover a new house and a few bats will likely move in the first year and you should have plenty in the second season.

Mounting Bat Houses

Sun 
Mount bat houses in the sun.  Except for extremely hot climates, bats need the sun's warmth all day, especially nursery colonies.  In moderate climates, paint houses black.  Nurseries must be warm enough for pups to grow quickly.

Water 
Odds of attracting bats increase with close proximity to water.  That's where the flying bugs are.  A balance of foliage is good.  Big Brown Bats usually feed within 1/2 to 1 mile of their roosts, rarely further.  Other bats travel less. 

Height 
Mount houses at least 12 to 14 feet high.  Higher, as much as 20 feet is better.  Have a professional mount a house if you are not experienced - it's never worth the risk.  Carpenters or electricians will often mount them for free just for the novelty.

Structure 
Attach houses to a sturdy metal pole or the south side of a building.  Metal poles and the cliff face simulation of a building wall deter intruders.

When 
Spring is best, but even though Spring may be over, bats will still likely discover your new bat house and a few will possibly even move in.  Sometimes bats move into a bat house within a few weeks.

How Many
Two bat boxes mounted back to back, one bat box facing north and one facing south seems to work well.  Wait with more until you see the results.

Nursery Colonies

The reason for mounting 2 bathouses is because males and females of many bat species typically divide into nursery and bachelor colonies for much of the summer.  Males often spend the summer alone or in small bachelor colonies. 

Most bats breed in the fall and pups are born in spring or early summer. Female bats usually give birth to one, sometimes two pups per year and raise them in nursery colonies with other females.    Pups feed on their mother's milk and fly within a few weeks after birth.

Males and females start mixing again after the pups are weaned and nursery colonies begin to break up in Autumn.

148 species live in North America, 140 inhabit Mexico, 19 inhabit Canada, and 45 inhabit the U.S.  10 U.S. and Canadian species nest in bat houses. See Bat Maps

                 10 Bat Species That Nest In Bat Houses
 

Little Brown Bat   Image

The Little Brown Bat, the species most often attracted to bat boxes, inhabits most of wooded Canada and northern U.S.  Nests in tree cavities and often in sheds and attics.  Forage in open spaces for flies, moths, mosquitoes, and aquatic insects near or over water. 

Big Brown Bat  Image

The Big Brown Bat roosts in tree cavities, buildings and under bridges in a wide variety of habitats in all lower 48 states, Canadian provinces and Mexico, very often in close proximity to humans.

                 

Eastern Pipistrelle

Eastern Pipistrelle inhabit buildings and forests in eastern Canada, most of the states east of the Rockies and Central America and hibernate in caves and abandoned mines.

Yuma Myotis

Yuma Myotis inhabit the West Coast States and some of the southern Rocky Mountain states most often in wooded areas where they prefer to forage for a variety of insects.  They roost in caves, abandon mines, buildings and under bridges.  They prefer forested areas

Eastern Long eared Bats    Image

Eastern Long eared Bats inhabit most of the eastern U.S. as far south as from Arkansas to Georgia and from Newfoundland to eastern British Columbia.
               

Pallid Bats     Image

Pallid Bats roost in rock crevices, buildings and under bridges in most of the states west of and some of the Rocky Mountain states, central and eastern Canada and Mexico.  They are ground feeders catching beetles, crickets and grasshoppers which they can hear walking!

Southeastern Bats

Southeastern Bats live in caves, abandoned mines, tree cavities in woodlands, buildings and under bridges.

Cave Myotis

Cave Myotis congregate in the thousands in caves, abandon mines, buildings and under bridges in the southern Great Plains and the arid Southwest from Kansas, Oklahoma and West Texas to Arizona

Evening Bats

Evening Bats inhabits tree cavities, under bark and in wooded areas and sometimes in buildings in southeastern U.S. and Mexico and migrate south before cold weather.

Mexican Free-tailed Bats     Image

Mexican Free-tailed Bats live in colonies numbering from a few hundred to millions of individuals in caves, abandoned mines, tree cavities, buildings and under bridges.  They inhabit woodlands, mountains, lowlands, and deserts throughout middle and southern U.S. and Mexico, although they are most numerous in Texas where millions migrate every year. 
 

Some bats can live up to 30 years!                                

Bats emit high frequency sounds and locate insects by listening for and detecting the source of the reflected echoes

Bats usually scoop insects into their tail or wing membranes.

Bats can fly 40 miles an hour.

Where there are no insects in winter climates, bats hibernate or migrate.

                             "Eye of newt and toe of frog,
                              Wool of bat and tongue of dog"

                                                         William Shakespeare