April 23, 2014

Cozy homes for nocturnal bug munchers

As published in the Erin Advocate

Bats may not be the most attractive of creatures, but any critter that can eat up to 5,000 mosquitoes per night without harassing humans does qualify as a friend of mine, and is welcome to hang out in my back yard.

The Countryside Stewardship Team at Credit Valley Conservation (CVC) points out that 7 of Ontario’s 8 types of bats live in the Credit watershed, and that none of them drink blood.

A little brown bat being banded during a study last year
at Century Church Theatre. They have 38 sharp teeth,
which are very useful for eating hard-shelled beetles.

“A single lactating Little Brown Bat can eat up to 5000 mosquitoes per night,” says the CVC team. That’s a lot, considering the bats only weigh between 8 and 15 grams. “They are also a great help to agriculture in controlling insect pests and helping to pollinate crops.”

Bats have had a rough time in recent years, with a disease called “white nose syndrome” that causes them to wake up too early from hibernation in caves and mine shafts. Millions of them have died, but those that survive return in the spring to large roosting sites such as Hillsburgh’s Century Church Theatre, or seek out smaller homes.

That’s where humans can help bats, and themselves, by building backyard bat boxes out of cedar or plywood (non-pressure-treated).

Bat houses in the Town of Mono.

The suggested size is at least 24 inches tall, 13 inches wide and 3 inches deep, with a ceiling and a sloped roof above it, an entrance at the bottom just .75-inch wide (to keep predators out) and a thin air vent about 6 inches above the entrance.

A bat house can have one or multiple narrow chambers for them to sleep during the day, including plastic mesh on the front and back for their claws to grip.

Houses should be caulked to keep rain out, and coated with black latex paint in the Southern Ontario climate. They should be mounted on poles or the sides of buildings where they will get maximum direct sun exposure, at least 12 feet above the ground.

Bats prefer locations that are within half a kilometer of a stream, river or lake. They are mammals (not rodents) that live about 7 years, and sometimes up to 30 years, with 1,240 separate species.

About 70% eat insects, and most of the rest eat fruit. Vampire bats, native to Mexico and South America, do have a taste for blood, making small bites on sleeping animals.