The most common bats in southern B.C. are the little brown bat and the large brown bat, two of the 16 species found in the province. All bats are protected by the provincial Wildlife Act as they are one of the most beneficial animals. A single brown bat can capture 600 mosquitoes an hour, a colony of 500 bats, a million insects a night.
Bats found in buildings are usually there as a temporary daytime roosting site, a nursery to rear their young or as a hibernation site. Bats are nocturnal and will not leave a roosting site if there is bright light. Bats are mammals and can carry diseases and parasites the same as other mammals and in rare cases, rabies. In reality, people are more likely to contract rabies from their family pets than from bats. The biggest area of concern, however, is the accumulation of droppings and urine in the areas where the roost is located, specifically if the roost is in a residential attic.