 - Bat
Control
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When people think about bats, they often imagine
things that are not true. Bats are not blind. They are
neither rodents nor birds. They will not suck your
blood--and most do not have rabies. Bats play key roles in
ecosystems around the globe, from rain forests to deserts,
especially by eating insects, including agricultural pests.
The best protection we can offer these unique mammals is to
learn more about their habits and recognize the value of
living safely with them.
As with any animal, bats should not be
handled for obvious reasons. Bats can have rabies and other
diseases and parasites. Bats should only be handled by
professionals.
People cannot get rabies just from seeing a
bat in an attic, in a cave, or at a distance. In addition,
people cannot get rabies from having contact with bat guano
(feces), blood, or urine, or from touching a bat on its fur
(even though bats should never be
handled!).
How can I keep bats out of my
home? Some bats live in buildings, and
there may be no reason to evict them if there is little
chance for contact with people. However, bats should always
be prevented from entering rooms of your home. For
assistance with "bat-proofing" your home, contact our
service for more information and estimates.
How can I safely capture a bat
in my home? If a bat is present in your
home and you cannot rule out the possibility of exposure,
leave the bat alone and contact our service for assistance.
If professional help is unavailable, use precautions to
capture the bat safely, as described below.
What you will need: leather
work gloves (put them on) small box or coffee can
piece of cardboard tape
When the bat lands, approach it slowly,
while wearing the gloves, and place the box or coffee can
over it. Slide the cardboard under the container to trap the
bat inside. Tape the cardboard to the container securely,
and punch small holes in the cardboard, allowing the bat to
breathe.
Are bats
beneficial? Yes. Worldwide, bats are a
major predator of night-flying insects, including pests that
cost farmers billions of dollars annually. Throughout the
tropics, seed dispersal and pollination activities by bats
are vital to rain forest survival. In addition, studies of
bats have contributed to medical advances including the
development of navigational aids for the blind.
Unfortunately, many local populations of bats have been
destroyed and many species are now endangered.
Where can I learn more about
bats? Contact your state or local wildlife
conservation agency or Bat Conservation International:
Bat Conservation International, Inc. P O Box 162603
Austin, Texas 78716 www.batcon.org
Background Information
Bats are the only mammals capable of actual flight. Eight
species of bats can be found in Connecticut:
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Little Brown
Bat (Myotis
lucifugus)
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Big Brown
Bat (Eptesicus
fuscus)
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Eastern
Long-eared Bat (Myotis
septentrionalis)
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Eastern
Pipistrelle (Pipistrellus
subflavus)
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Silver-haired Bat (Lasionycteris
noctivagans)
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Hoary Bat (Lasiurus
cinereus)
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Red Bat (Lasiurus
borealis)
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Indiana Bat
(Myotis
sodalis)
The 2 most common bats in Connecticut are the little brown
and big brown bats. The 6 remaining species are less common
and seldom seen. Silver-haired, hoary and red bats are
tree-roosting bats and are listed as Connecticut species of
special concern. The state and federally endangered Indiana
bat was recently found hibernating in Connecticut. No
confirmed sightings of the eastern small-footed bat (Myotis
leibii) have been recorded
here in several decades. It is a Connecticut species of
special concern.
Description
Bats are furred, warm-blooded mammals with body lengths of 3
to 6 inches and wingspans ranging from 8 to 16 inches. The
bones in a bat’s wing are similar to those in human arms and
hands. The fingers are extended and connected by leathery,
elastic skin that grows from the sides of a bat’s body.
Their thumbs are free from the wing membrane and have claws
for grasping.
Bats have good eyesight and rely on vision for long-distance
orientation. For short-distance navigation and catching food
at night, they use echolocation. This sonar system helps
bats, like dolphins, locate targets and background objects
from the echoes of ultrasonic sounds. These ultrasonic
sounds are given slowly when a bat is foraging and quicken
as the bat pursues and captures an insect. Detection,
pursuit and capture of an insect take about 1 second.
Connecticut’s
bats are primarily insect eaters. An exception is the hoary
bat, which also eats other bats, namely the eastern
pipistrelle. Bats are mostly nocturnal and almost always
feed "on the wing." They use their wings, the skin around
their tails and their mouths to catch insects in flight.
Bats are the only major predators of night-flying insects,
making them beneficial to man in several ways. They consume
many agricultural pests such as cutworm and corn borer
moths, potato beetles and grasshoppers. Mosquitoes and
similar "people" pests are eliminated much more efficiently
by bats than by birds or expensive bug zappers.
Interesting Bat Facts
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In general,
bats are not dangerous. Like any other mammal, they can
carry rabies, although less than 1 percent of all bats
are infected with the virus. More people die annually
from dog attacks, bee stings, lightning and household
accidents than from bat-transmitted rabies.
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Bats do not
get caught in people’s hair. Bats that swoop near people
are usually after insects such as mosquitoes.
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A single
little brown bat can eat 1200 mosquitoes in an hour.
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There are
almost 1,000 different species of bats in the world, but
only 8 are found in Connecticut.
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Only 3
species of bats feed on animal blood. These vampire bats
prefer to drink cattle blood and are only found in Latin
America.
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The smallest
bat is the size of a small mouse; the largest, a fruit
eater, has a 6-foot wingspan.
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Bats have
varied diets: 70 percent eat insects; many tropical
species eat fruit or drink flower nectar; some bats even
catch frogs and fish.
Nuisance Problems
The presence of bats can be detected in several ways. At
dusk, when bats leave roosts to feed, they may be seen
exiting through eaves, vents or from behind shutters or
siding. Noise from large colonies may also announce their
presence. Droppings and dark brown stains may appear near
eaves and beneath entrance holes and roosts. Bat droppings
(guano) are easily crushed, revealing shiny bits of
undigested insects. They are never white or chalky in
appearance, as are the droppings of birds.
The 2 most common bats involved in nuisance complaints are
the little brown bat and the big brown bat. The little brown
bat ranges from 3.1 to 3.7 inches in length and has a
wingspan of 8.6 to 10.5 inches. Big brown bats range from
4.1 to 4.8 inches in length, with a wingspan of 12.1 to 12.9
inches. Big brown bats can readily be distinguished from
little brown bats in flight by their larger size, slow
wingbeats and audible chatter.
A single bat that enters a home can often be removed easily.
Closing off doorways to the room containing the bat and
opening a window will usually prompt the bat to fly outside.
A large jar or can may also be used to remove a bat. Move
toward the bat slowly so that it is not startled and gently
place the can over it. Slide stiff paper or cardboard under
the can’s opening, using it as a lid when removing the bat.
Heavy leather gloves should be used to remove a bat by hand.
Bats, like all wild animals, may bite when handled and
should not be removed bare-handed. Remember that bats, like
other mammals, may be a source of rabies. The rabies virus
is found in saliva and may be transmitted through the bite
of an infected animal.
If you are accidentally bitten while handling a bat, make
sure the bat is saved for examination. Immediately wash the
bite with soap and water and seek prompt medical advice.
Non-bite exposures can also occur and should be treated in
the same manner as a bite. A non-bite exposure occurs when
saliva or brain tissue from an infected animal enters
scratches, abrasions, open wounds or mucous membranes (nose,
mouth, eyes).
Most colonies of bats are small and often remain unnoticed
for many years. Large colonies residing in an attic or wall
may become a nuisance because of noise and unsightly guano
accumulations. Eviction and exclusion of roosting bats are
the only safe, permanent solutions to a nuisance problem.
Exclusion and Bat-proofing
One of the simplest techniques for solving nuisance problems
is letting the bats exit on their own and then preventing
their re-entry to the roost. Little brown bats do not winter
in buildings, so bat-proofing can be done after they travel
to their winter roost site. Big brown bats usually travel to
other roosts also, but they have been known to use building
roosts in the winter. If nuisance problems involve big brown
bats or if rapid exclusion is necessary, the first step is
to find the exit(s) by watching the bats emerge at dusk.
Stains from body oils or droppings may help pinpoint exits.
Exclusion
should not be done from June through mid-August, as
flightless young may be trapped and die in the roost,
causing severe odor problems.
It you wish to hire someone to exclude and bat-proof your
home, it is best to seek a specialist such as Wildlife
Control Services, LLC. If the bats need to be trapped or
handled, the specialist must be licensed by the DEP Wildlife
Division. Beware of scare tactics, and remember:
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Bats do not
multiply like rabbits.
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Even sick
bats rarely attack people or pets.
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Bats are not
attracted in hordes by the scent of other bats.
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Bats have
very few parasites, so additional spraying for parasites
is not necessary.
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Permanent
physical exclusion is essential for any bat control job.
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The use of
poisons to eliminate a bat colony is illegal without a
special permit.
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Bat guano is
not "toxic"
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Rabies rates
in bat populations are not increasing
Be careful when removing bat droppings from indoor roosts.
Histoplasmosis, a fungal disease associated with the
droppings of birds and bats, can result from the disturbance
of dried droppings. Disturbance causes the fungal spores to
become airborne, and spores entering the lungs can cause
respiratory problems. However, histoplasmosis is seldom
fatal; mild cases are common and often go unnoticed. Hot,
dry attics rarely allow the spores to survive; thus, this
disease is much more common in chicken roosts than in indoor
bat roosts. Histoplasmosis is easily preventable--wearing a
mask when removing accumulations of droppings prevents
inhalation of the spores.
Bat Houses
If you want bats out of your house but would like to retain
them for their excellent insect control abilities, why not
consider building or installing a bat house after the bats
have been excluded. Bat houses, much like bird houses,
provide artificial roost sites for bats. They have been
widely used in Europe for over 60 years. Much has been
learned in recent years about bat roosting preferences. The
following factors are critical to the success of bat houses:
maintaining suitable temperature ranges, the distance to
food and water, the size and shape of inner roosting spaces
and the roughness of clinging surfaces.
Bat house designs range from simple and small-scale to large
and complex. Two of the simpler designs are shown on
opposite page. The small bat house provides only one size
roosting space and accommodates fewer bats. The large bat
house provides many roosting options and is ideal for larger
nursery colonies of females and young. Below are tips for
constructing and installing a bat house:
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Use the
roughest sides of the wood on the inner areas of the
house. It is also a good idea to horizontally groove
inner surfaces for footholds or attach non-metal
screening to provide toe holds. This is also important
for landing areas below the entrance.
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Caulk all
outside seams to limit air flow. This helps trap the
bats’ body heat inside the house. Sealants approved for
aquarium or kitchen use are best.
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Place tar
paper or dark shingles on the top and 4 to 6 inches down
the side to increase inside temperatures. Nursery roosts
often require temperatures of 90 degrees F or more. A
dark stain also helps increase the temperature.
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Hang houses
10 to 15 feet above ground. South and southeast
exposures are best for providing maximum thermal gain.
Bats prefer houses that get at least 6 hours of sunlight
a day.
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If possible,
protect the house from prevailing winds and provide an
unobstructed approach.
Bat houses attached to the sides of buildings have had the
greatest reported success. Free-standing poles in open areas
also work, but tree-mounted houses generally remain unused.
Bat houses placed near water or wetland areas often are most
successful. Installing a bat house before April improves the
chance of occupancy. Don’t be discouraged if bats do not
immediately move into their new home. It is not unusual for
a house to stand empty for at least a year before it is
used.
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