Bats - Enjoy them from a Distance

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Fall 2009



Although bats are excellent pest controllers (they can eat three times their body weight in insects every night), they also have a dark side: they occasionally carry rabies.


Fortunately, rabies is rare in bats, and documented cases of bats passing rabies on to humans are far and few between. (See Bat Rabies – The Facts) In Ontario, 95% of rabies positive bats are big brown bats.


There are eight different species of bats in Ontario: big brown, little brown, eastern pipistrelle, silver-haired, hoary, red, small-footed, and the northern long-eared. Of the different species of bats, only two will typically roost in peoples’ houses: the big brown bat (13-25 grams) and the little brown bat (4-8 grams). The big brown bat (13-25 grams), probably the most adapted to civilization, will hibernate in colonies over winter in houses, in addition to caves, as well as roost in houses during the summer. The other communal bats, such as little brown (4-8 grams), eastern pipistrelle and small-footed, will typically roost in caves during the summer and hibernate there over winter, although little brown bats have also been know to roost in houses.  The more solitary bats, such as silver-haired, hoary, red and northern long-eared will tend to live in trees or brush in the summer. Some of these bats, like the silver-haired, red and hoary, will migrate long distances for the winter months, some as far south as the Gulf of Mexico.   Despite their size, bats are long-lived and reproduce very slowly. Most species actually produce only one offspring per year, making bat conservation essential. Bats help reduce the insect population and are vital to the ecosystem.


A major difference between bats and other rabies carriers is that bats are small and can bite a human without the person ever knowing it. If you ever wake up and find a bat (dead or alive) in the room with you, or a bat is found in a room with an incapacitated person or unattended child, then the possibility exists that a bite has occurred. Bats have very small bites that can go undetected. You should contact your closest health unit.


Bats, which feed on flying insects, cannot be tempted to take baits containing rabies vaccine. The MNR Rabies Research & Development Unit has focused on eliminating terrestrial rabies from foxes and raccoons. The arctic fox strain used to result in larger numbers of rabid animals in southern Ontario than in any other state or province in the U.S.A. or Canada.


Bat-proof your home. If you need assistance, contact an animal-control or wildlife conservation agency. Do not use pesticides or other poisons to control bats. Poisoned bats may fall to the ground where children or pets may pick them up.


If you find a bat in your home and are absolutely sure that there was no human or animal contact, try to confine the bat to one room, turn out the lights, and open a window. The bat should fly out early in the evening. Be sure to wear gloves and other protective clothing at all times.


If you have children, warn them to stay away from animals. If a bat is wandering around in daylight, acting strangely, or crawling around on the ground, it may be rabid. Stay away.


Since bats are capable of transmitting rabies to domestic pets, it is important that your pet’s vaccination shots are up-to-date. Remember that it is also the law.

If bats are found in your home, seek expert advice:


MNR District Offices
Bat Conservation International



Natalie Gorman
Ministry of Natural Resources
(705) 755-1551


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