All About Bats

In the past, myth and superstition have caused humans to fear bats. However, the more we learn about bats, the more we learn to value them! Minnesota bats eat flying insects, and so offer excellent natural pest control. A single little brown bat can eat 1200 mosquitoes an hour, while big brown bats eat harmful crop pests, such as Cucumber beetles, June beetles, and cutworm moths.

bat02Below is some useful information for what to do if you come across a bat, or if a bat is inside your house.

Bats inside the House

Sometimes a bat finds its way inside your home.  It’s usually either a young bat that’s gotten lost, or an adult that’s come in through an open window or door.  Fortunately, it’s easy to get the bat back out again.

  1. Stay calm. The bat is trying to find its way out, and it is frightened too!
  2. Turn on the lights so you can see.
  3. Close doors to adjoining rooms to isolate the bat. Open doors and windows to the outdoors. If possible, turn on an outside light to help the bat see the exit.
  4. The bat will probably fly out an open door or window in a few minutes. If not, go to step 5.
  5. Put on a pair of work gloves, get a small cardboard box, and wait for the bat to land. Place the box over it and gently slip a thin piece of cardboard under the box, being careful not to damage the bat’s legs or wings.
  6. Take the box outdoors. Set the box on its side in a high place so the bat can swoop down from it to start its flight.

If the bat doesn’t fly away, see directions for ‘Injured Bats’.

NOTE: Do not release bats in winter, during the day, or in cold or inclement weather.

Injured Bats

If you find an injured bat, use heavy work gloves to pick it up and place it in a cardboard box with a few tiny holes for ventilation.  Tape the box closed, and place it in a warm, dark, quiet place away from pets.  Get the bat to a wildlife rehabilitator as soon as possible.  NEVER try to care for a bat on your own; bats require very specialized care.

White-Nose Syndrome

Since 2006, WNS has killed more than 5.7 million bats in eastern North America. WNS is caused by a  cold-loving fungus from Europe (Geomyces destructans).  It was first discovered in New York caves in 2006, when it killed half of the wintering bats. The disease’s name refers to the white fungal growth found on the noses of infected bats.

WNS is killing hibernating bats in 16 states and 4 provinces, wiping out 90-100%  of bats in affected caves, and spreading rapidly.  The fungus can be spread from cave to cave and bat to bat.  WNS does not infect humans.

Bats and Rabies

Fewer than 1 in 1000 bats carries rabies.  Rabid bats are usually not aggressive and soon die.  If you or your pet is bitten or scratched by a bat, or if bat saliva gets in your eyes, nose, or mouth, report this to your local health department and your doctor immediately.  If possible, capture the bat so that it can be tested.  Do not damage or freeze its head.

Having a Bat Problem?

Many people are uncomfortable sharing their house with bats.  Luckily, there are safe,  cheap, and humane methods for excluding bats from your home, though timing is crucial.  Exclusions can be performed in early spring after insects have appeared, and in the fall.  NEVER do bat exclusions during June, July, and August when young bats cannot yet fly.

Exclusion is the ONLY effective to permanently remove bats from buildings.


Steps for Proper Bat Exclusion

  1. At sunset, search the exterior of your house for the entry/exit point. Bats can fit through a hole the size of the tip of your thumb and move very quickly, so look closely!
  2. Mount a bat house close to the hole and wait 3-4 days until the bats are accustomed to it.
  3. On the afternoon of the 4th or 5th day, cover the entry/exit hole with a square piece of
    screen mesh. Using duct tape, secure 3 sides of the mesh to the house, leaving the bottom untaped and loose enough for the bats to crawl out. Bats will leave at dusk, will be unable to return, and will look for the nearest place to roost–the bat house!
  4. Leave the screen mesh up for at least 1 week to ensure that all the bats have safely left your house. After this, you may permanently seal the hole.

It’s cheap and easy to humanely exclude unwanted bats, and the time and effort you spend will be amply repaid by the moths, flies, and mosquitoes they eat. In addition, you’ll set a great example for others when you show them how to peacefully coexist with bats.