There are more than forty species of bats found in North
Attics make excellent places for colonial bats to roost and
raise young. Individual bats do occasionally fly into houses via a window or an
open door, but normally a bat in your house is an indication of a colony
somewhere in your home. Chimney flashing, soffits, and wood siding are the
likely entry points.
Bats need to regulate their body temperature, as do all
animals. Living in an attic, this can become a challenge. A colony in an attic
may need to ascend (to keep warm as heat rises) and descend when temperatures in
the attic become too hot. During this process, they may sense cooler/warmer air
currents emanating from the living space of your home, for example, warmer air
in the winter (Dec -Feb) and cooler air in summer (July-Aug).
Bats need only an entry point of .5 of an inch or more to
access the living area of your home. The most likely entry points to the living
area of your home are interior rock walls, such as a fire place, and interior
wood finishing. Heat and cold expands and contracts wood seasonally creating
If you do encounter a bat in your home, a butterfly net and
a pair of gloves are a good way to extract it. If you are not sure how long the
bat has been in your home (and it is contained), your local wild life
rehabilitation center should be contacted before release (e.g., WildARC for the
greater Victoria area). Utmost caution should be taken when attempting to
remove a bat from your home. Bats are the only animal known to carry rabies on Vancouver
Island. Although it is very rare, infected bats can potentially infect humans
just by touch (saliva is a vector and bats groom themselves with their tongue).
EXCLUSIONS. Bats are federally protected. No lethal control
of bat colonies is warranted or excused. Besides, the potential for serious
injury or illness to humans occupying a house treated with the toxicants that
are used illegally to control bats is far greater than any possible harm or
risk the animals themselves could pose.
Bats should be evicted from a building only when it is known
that no young animals are present. From May through August, young bats remain
flightless in the colony. Any attempt to exclude them during this duration will
likely trap young/adults, and likely destroy the colony. Keep in mind, these
animals are voracious insectivores. Little brown bats tested in controlled
indoor enclosures have been documented eating upwards of 600 mosquitoes per hour!
Attempting an exclusion should begin in September. Check valves or one way
doors on all entry points will ensure a safe and humane exit from your home.