World of Bats

Introduction to Bats


When some people hear the word “Bats”, it sends chills down their spines and raises the little hairs on the back of their necks. Traditionally in western countries bats are portrayed as evil, dirty, blind, disease carrying, flying rats that will fly into your hair. The primary reason for their fears stems from the many exaggerated old myths and Hollywood stories. We all remember seeing Dracula turning into a bat, flying into the unexpected victimʼs room at night and sucking all the blood out of their body when they are sleeping. It is interesting to see the contrast in the beliefs in other areas of the world. For example in China bats have a much different representation. They see bats as sign of bravery, strength, health, wealth, fertility and good luck. This is evident when you see bat symbols decorating their jewelry, pottery, weapons, drapes, and furniture.

Many people assume that the closest relative to bats are rodents. Even though rodents look similar to some bats, they are not their closest relative. If you look carefully at the bat’s body you can see that they have a very similar skeleton to primates. The greatest difference is that they have very long fingers with a thin membrane of skin stretched between each of the four fingers and body. This frame covered with skin and strong muscles, work as wings and allow the bats to fly. Bats are the only mammals that truly fly. We have all heard of flying squirrels but they do not fly, they just jump and glide.

Bats are a very successful, diverse, nocturnal group of mammals with approximately1200 living species (See Bat Photos). Flight makes bats unique among mammals and their mobility corresponds to a very wide distribution, found almost everywhere in the world except the Arctic and Antarctic. Besides the harsh cold temperatures, there is also no food. The Bat world has two primary divisions, the Mega-bats/flying foxes (150 species) and Micro-bats (1050 species).


Flying Foxes


The Mega bats (flying foxes) occur only in the Old World tropics and consist of 150 different species. They have dog like faces and are characterized by simple ears, large eyes, and large size. One species has a two meter wing span and weigh over 1kg. Very few of the flying foxes have the ability to echolocate. All flying foxes eat fruit, flowers, nectar, pollen and many species are known to travel long distances in search of food.





Micro bats

The Micro bats are more diverse, numerous and all of them can echolocate. Most of the micro bats eat insects, but others eat fruit, nectar, pollen, fish, other mammals, small reptiles, amphibians, and blood. Flight and echolocation have permitted these bats to exploit roost environments unavailable to most other vertebrates. Micro bats live in the foliage of trees, caves, leaves, rock crevices, tree cavities, bamboo and man-made structures.


Canadian Bats

In Canada we have a total of 19 species of bats and all eat insects. In Ontario we have 8 species and in the Georgian Bay/Muskoka region we have two primary species. They are the Big Brown bat (Eptesicus fuscus) and the Little Brown bat (Myotis lucifugus). Both look very similar with the greatest difference being size. Big Brown bats are a medium to large species, brown fur, with a wing span of 32-39 cm, forearm of 42 to 51mm and weighs 14 to 30 grams. Little Brown bats are small to medium sized species, with a wing span of 22-27 cm, forearm length 34 to 40 mm, fur is olive brown to dark brown, and weighs 5 to 14 grams.

Other species found in Ontario are the Long Eared Bat (Myotis septentrionalis), Eastern Pipistrelle Bat (Pipistrellus subflavus), Silver-haired Bat (Lasionycteris notivagans), Red Bat (Lasiurus borealis), Hoary Bat (Lasiurus cinerus) and the Evening Bat (Nycticeius humeralis).

Most of the bat species in Ontario migrate south to warmer climates during the winter months.However some species such as the Big Brown, Little Brown and Silver-haired bats hibernate in Canada for the winter. Some will fly great distances (250 km) to find a winter hibernacula and some prefer to stay in the same roost site year round.

The primary reason both of these species are seen on a regular basis is because they are often found roosting in man-made structures such as buildings, bridges, and decks. Their common name is also the “House Bats”. Man-made structures provide ideal roosting areas because they often have openings larger than 5 mm (¼ inch). Holes which are the size of your baby finger are large enough for the bats to gain access.

These structures provide protection from predators, shelter from the elements, are generally located close to food and water, and the temperatures are ideal for the birth and rearing of young bats.


Bat Problems & Diseases

There can be problems resulting from having bats living in people’s homes. They can be noisy, unintentionally fly in human living areas and urine and droppings (guano) can accumulate producing a very strong unpleasant odor. The droppings can also provide a medium for the disease Histoplasmosis.

Histoplasmosis is a fungus disease that affects the lungs with symptoms similar to tuberculosis and in severe cases can affect other organs of the body. The fungus grows in bird and bat droppings (guano)(photo #9). Areas where guano has accumulated should be avoided. If removal of droppings is attempted, gloves and protective clothing should be worn, and at a minimum, a respirator with minimum of 2 micron filter be used.  In some cases an alternate breathing source is recommended for clean-up. After the clean-up has been completed, the entire area must be sprayed with disinfectant and fungicide. It is highly recommended that professionals be consulted in regards to the exclusion of bats and the removal of guano.

For further reading view research and news section and view the following websites:

Bat Problems and Diseases




Rabies is a viral disease that attacks the central nervous system of warm-blooded animals and if untreated can cause death. The incidence of rabies cases in Canada and the United States is extremely low and the animals that most often transmit the virus are foxes, skunks, raccoons and bats. According to the Canadian Food Inspection Agency 57 bats tested positive in Ontario for rabies in 2007.

The rabies virus is transmitted when saliva from an infected animal bites an individual or the saliva comes into contact with a scratch, open wound or mucous tissue such as the eyes, nasal cavity or mouth. If an individual suspects that they have been infected, they should contact there doctor as soon as possible.
The good news is treatment is not the many painful needles in the stomach any longer. Often the treatment only requires 2 needles in the arm or buttocks.
Only a few species are large and strong enough to break the human skin, however all bats should be handled with gloves. Any bat acting abnormally (lying on the ground and not flying) should be handled with great care.

For further reading please view the following websites: A) B) C)


Bat Bugs


Bat bugs are blood parasites that normally feed on their natural host, bats. It is important to note that these are NOT bed bugs and different solutions are required for both species. A biologist or pest control professional will require a microscope to properly identify the species.

Sometimes bat bugs are found within homes when large populations of big and little brown bats are living within a building. As a bat biologist and someone that handles bats on a regular basis I have seen these parasites on a regular basis. Fortunately I have rarely been bitten and do not have an allergic reaction to these bugs. It has been my experience that after the bats have been excluded from buildings the bat bugs also seem to disappear. However, there are situations that specific insecticides may have to be sprayed to kill these pests and prevent them from biting people. Remember, bats must be excluded before any chemicles are used!

For further reading please view the following websites: A) B)


Dermestid Beetles

These round or oval shaped beetles have been found living in the guano of bat populations. They are usually black or brown but can also be brightly coloured and complex patters. The larvae of these beetles have been found leaving the guano where they will enter the living area and eat feathers, hair, fur, skins, horns and some species will feed on carpets, rugs, and furniture. Museums often use this some carrion-feeding species to clean the soft tissue from animal bones.


Bat Exclusions

It is sometimes necessary to exclude bats from man-made structures. If bats have chosen a particular building to roost, killing the bats does not take care of the problem and most likely they will continue to return year after year.

The most effective measures of excluding bats are ones least harmful to the bats. If improper measures are taken bats may become trapped in walls and worsen the problem. My experience as a biologist and as a professional in wildlife control has found that the use of mothballs, bags of bleach soaked cloths, lights left on in attics, and tennis rackets do not solve bat problems. If bats are living in the building chances are that mice, insects and weather also have access and creating health hazards or destroying the building (i.e. rot, black molds) . A very careful and detailed inspection of the building is required. All holes of the building which are 5 mm (1/4 inch) or larger must to be closed. To prevent bats from becoming trapped inside buildings, an exclusion valve (one-way door) needs to be installed on the primary ports (access points). A common mistake is that people feel that only 1 one-way door is required. In some situations we have needed to install over 25 one-way doors to ensure all bat were excluded safely.

My previous research and work conducted by other biologists suggests that urine, guano and glandular secretions play an important role in communication. These olfactory cues may be used in scent marking a specific territory as “home”. Therefore all olfactory cues created by guano, urine and glandular secretions should be removed. Specific safety procedures should be used when an individual is in close proximity to bat guano. See Histoplasmosis section for more information and health risks.

My experience with the exclusion process suggests that installation of alternate accommodations in the form of a bat house greatly helps ensure success. Refer to Bat house section for more details.

Bat Exclusions


Bat Conservation

Most people are unaware they may have these amazing creatures in their area because bats are nocturnal and they have hidden daytime roosts. Bats are extremely important to the environment. The over use of pesticides and destruction of roosts and direct killing of bats is having a severe impact on the bat populations. As mentioned before Canadian bats eat only insects.  A lactating female will eat over half her body weight in insects every night and a Little Brown bat can eat 1,000 mosquitoes in an hour. Bats can also act as an environmentally friendly measure to fight against diseases that mosquitoes may carry (West Nile Virus & Encephalitis). Bats are intelligent animals and choose their food according to availability and the calculation of energy expenditure. They will choose a moth or beetle before they choose a mosquito. The larger insects provide a greater nutrient reward for less energy expended. The destructive abilities of moths and beetles are often overlooked. Smaller bat species such as Little Brown bats will definitely eat mosquitoes; it is just not their only choice in meals.

The most effective conservation methods can be achieved by the protection of hibernacula, prevent the degradation of summer foraging habitats and roosts, installing alternate roosting sites such as bat houses and through public education.

Bat Conservation


Status of White-Nose Syndrome


White-nose syndrome is devastating bat populations across North America and continues to spread throughout Canada and United States. Millions of bats have been found dead on the floors of their hibernacula. Maternity colonies are also declining and therefore their birthrates. More funding is required for both monitoring and research to develop solutions to help both the bats and ourselves.
Evidence suggests that the deadly fungus was introduced by people neglecting to follow proper decontamination protocol before entering new caves. The spores of the fungus causing WNS are picked up on the boots and clothing of cavers and later transferred to new locations. Because bats live in close proximity to one another, the fungus and therefore the disease has spread like wildfire throughout populations. At this time no solution has been found to safely kill the fungus or to cure the bats.

More dead and infected bats have been located in hibernation sites across Canada and United States. It is unclear how many bat populations have been infected because we only know the locations of a very small percentage of hibernacula. Most of the hibernation sites that have been identified have had gates put in place to keep people out of them and stop further contamination. However, funding is desperately needed for both MNR and biologists to monitor bat populations and develop strategies to save them.

It is very clear from my bat inspections of cottages and homes across Ontario that populations do not match evidence left by the previous year’s maternity colonies. At many sites where the guano and other signs suggest there should be population 50 to 100, I am finding only a few, if any bats. I am also getting several calls from concerned individuals who no longer see bats flying in their areas. Many of these calls are coming from Georgian Bay and Muskoka. Fortunately, I am finding some areas that show healthy populations. One such population near Espanola exceeded 500 little brown bats and no sign of WNS (video of 500 bats).
These difficult economic times have caused governments to focus on job creation rather than ensuring the survival of important species in the ecosystem. Politicians need to remember the impact these amazing animals play in controlling insect populations. Consider the stress and costs on the health care system if there is an increase in diseases carried by mosquitos, food costs if crops are destroyed by beetles, costs of spraying poisons to kill insects or ecotourism dollars if forests and plants area killed by moths. The department of Agriculture in the United States has calculated that the millions of bats that have already died will result in over 1 billion dollars needed to make up for their natural control of insects.

The bats are defenseless against WNS and without immediate attention, we will see more species move to the endangered species list. It is not too late to help these incredible animals of the night. If you have bats living in your homes or cottages, they can be relocated to bat houses. Take time to educate yourselves and your families about the important roles bats play in our world. If you see any bats showing signs of WNS contact the University of Guelph or MNR. If you won’t do it for the bats, do for yourself and the future generations.


Special Thanks

Bill Bat Boy Enterprises has many people to thank for their love and support. First I would like to thank Dr. Brock Fenton who is one of the world leading authorities on bats and other wildlife. He is my mentor and inspiration. I would also like to thank Tamara and Bruce Jakes, Melanie and Rebecca Gillis, Fran Whittaker, Bill Handley, Buck and Kathy Blue, Don Kiley, Cottage Life Magazine friends, Gordon Galloway, Mandy Scully, Armando Rivero, Mat Andaloro, Grapefruit Moon friends, The gang at A Nerds World. Most importantly I need to thanks the “BATS”.