One-way bat door installation on a West Vancouver home

7 Steps to Managing Bats in Buildings

1) Know the Bat Basics

  • Bats are an ecologically & economically valuable group of species and are protected from harm
    by the BC Wildlife Act.
  • Bats can only be evicted in the appropriate season in a safe and sensitive manner.

2) Assess the situation

  • Where are bats roosting? The figure at right shows
    all the places bats could enter into or use in a house.
  • Is this a night roost? Night roosts are places that bats use temporarily during the night to rest between feeding bouts and include covered patios, door ways, and carports. Bats are rarely seen but droppings are observed in the morning.
  • Is bat eviction necessary? There’s no reason to evict them if there is little chance for contact with people.

3) Protect human living space

  • Prevent guano and bats entering inside the human living quarters by sealing spaces in floor joists and other entry points between roost and human living spaces.

4) Identify entry and exit points

  • Look for telltale signs of bat entry. These could include brown stains on walls where they squeeze in or accumulated guano below the entry point.

5) Install a bat house prior to eviction

  • Providing alternate roosting habitat increases the chances of successful and safe eviction of bats.
  • Install bat houses as high as possible (at least 3 1/2m (12’) high), on south facing exposures to receive at least 6 to 10 hours of sun. Bat houses should be installed in an uncluttered location without branches, buildings, or poles in front or below it.
  • Use only large, multi-chambered designs like a four-chamber nursery box or a two-chamber rocket box.
  • Designs can be found at www.bcbats.ca.

6) Evict bats using one-way exit device at appropriate time of year

  • Use a one-way exit device (such as a bat cone) to avoid trapping bats inside the building. This will allow bats to exit but not re-enter.
  • Evictions and exclusions are not permitted during the maternity season from May 1 to September 1. Ideally, evictions should take place in fall (September or October).
  • Check for presence of bats prior to doing an eviction.

7) Seal roost to exclude bats from building

  • Clean out guano and remove soiled insulation.
  • All entry and exit points have to be sealed completely as bats
    can enter through 12mm (1/2”) holes and cracks.

Additional Resources

  • Community Bat Programs of BC: www.bcbats.ca. Plans for bat-houses can be found here as well.
  • Bat Conservation International: www.batcon.org
  • Click on an image below to view or right click and select ‘save link as’ to download: