Got Bats? A BC Guide for Managing Bats in Buildings

The BC Community Bat Program  create a document to provide some basic information about bats and also some misinformation and misunderstanding. It has meant to help people to understand bats and what to do if they have some around or in their house.

Here are some facts about bats:

  • Bats are not rodents and are not concidered pests under BC law. They are classified as wildlife under the BC Wildlife Act and are protected from any harassment or killing.
  • Bats do not build nests and they do not dig, chew or claw their way throug structures like rodents, but use small openings that already exist.
  • Bats live long and have a low reproduction rate. Most species in BC usually have only one young per year. For this reason, it is very difficult for bats to recover from drastic population declines, caused by White Nose Syndrom, climate weather and anthropogenic affects.
  • All bat species in Canada are insectivorous, with a diet that includes insects and arthropods including mosquitoes or disease-spreading pests.
  • Bats are the only active flying mammals.
  • Bats inspired scientists since years, for navigational aids for the blind, blood-clot medications, low-temperature surgery, military sonar, and longevity research.
  • More than half of the sixteen species of bats in BC are threatened or a conservation concern.
  • Bats use as shelter, buildings and other human-made structures that offers them warmth and safety against predators. They roost under roofing, lashing and rafters, siding, behind shutters, fascia boards, in cracks of the chimney or walls or under a porch roof.
  • In BC, four bat species roost more regularly in buildings. The most common being the little Brown Myotis (Myotis lucifugus), the Yuma Myotis (Myotis yumanensis) and the Big Brown Bat (Eptesicus fuscus). Another species also sometimes found in buildings is the easiest to identify because of its long ears but more rare is The Townsend’s Big-eared Bat (Corynorhinus townsendii). Other species such as the Long-eared Myotis, the Fringed Myotis, the Long-legged Myotis, the California Myotis, the Western Small-footed Myotis, the Pallid Bats, the Northern Myotis, and the Silver-haired bats also use buildings as shelter but are not found as often.

Landowners who have some bats on their property can play an important role in bat conservation. Some of these roost could be housing a maternity colony.

Homeowners can easily enhance bat roosting habitat by following some simple recommendation. This is a useful source of information regarding bat colonies and the public is encouraged to spread and share information with its local bat association or any other active organism in bat protection.

There are three different type of roosts.

  • Maternity Roosts, are used by reproductive females to give birth and raise their youngs. They are generally easy to locate because of the noise and the abondance of guano.
  • Day Roosts, including maternity roosts, are used by bats during the day. Solitary bats such as male or non reproductive females will often stay under a loose bark or crevice, protected from the elements and away from predator reach.
  • Night Roost, are temporaly used during the nights. In between hunts, bats will rest for a certain time, leaving some clue the next day such as guano. Those roosts are often open spots such as above doors or under bridges

There are different 3 options for bat management

  • Option 1: Leave Bats Where They Are
    This is the best option for the bats. If possible, they should be left in their roost. Some action can be taken to reduce any annoyance they could cause such as sealing living quarters like attics, garage or chimneys (only from the top), mitigating guano and smell by removal and cleaning, reducing noise by improving the insulation and eliminating hazards that could kill bats.
    Most of the time people are happy to have bats on their proprety as they help to control insects.
  • Option 2: Exclude Bats
    This solution is used only if bats are causing annoying problems such as bats entering living quarters, the guano can’t be removed because of accessibility or the building needs renovation or demolition.
    Excluding bats does not involve any manipulation of bats or trapping, it means physically blocking the entrance and exit to the roost. This must be carefully planned and scheduled to avoid reproductive season.
  • Option 3: Enhance Bat Habitat
    Due to the status of bats, landowner having bats on their propriety would be playing a stewardship role for those animals. Roost can be improved by adding crevices, grips or darkness within the roost. Some structure can be added outside of the building such as bat houses, bat briks or by providing the natural stucture in the backyard such as water, trees, dead trees or rocks.

Addressing Health Concerns

The main health risk concerning bats in BC is rabies. Like all mammals, bats can contract this virus and die from it when contracted. They are the only animals in BC that act as a resservoir for rabies. However, the only way to contract the virus is through a direct contact, generallly a bite the rate however is extremelly  low. Public are advised to not handle bats without protection or supervision.

Bats are important animal that limits the number of insects including mosquitoes. They are important to have around.

  • Source Juliet Craig and Mike Sarell. February 2016. Got Bats? A BC Guide for Managing Bats in Buildings. Prepared by the BC Community Bat Program. Available at : https://bcbats.ca/attachments/GOTbats.pdf [Accessed 03/2021].