Bats in Your Belfry?

The phrase “bats in the belfry” was first uttered by a clever writer in 1899 as he humorously described a chaotic scene from an opera. It was picked up by other writers, re-used to indicate insanity or nuttiness and a new idiom was born, still in use today.

Bats actually do roost in belfries, in churches all over Europe, in caves, in attics of houses—essentially any dark space with an opening allowing them to enter. Colonies can be a few individuals up to large gatherings, numbering in the millions.

Globally, bats are facing threats created by the loss of habitat from deforestation and urbanization, diseases, cave and underground mine disturbances; in addition to the direct persecution of bats caused by ignorance.

Some Common Bat Myths

• Bats will suck your blood. Um, hogwash. Yes, there are vampire bats, whose primary food source is blood. These bats range from Mexico throughout Central and South America. Vampire bats feed primarily upon large mammals and will “shave” the area, if necessary, prior to making a small incision with sharp teeth and lapping up the blood. The incision is so small, in most cases, the animal is unaware of having provided blood to the hungry vampire.

• Bats will seek out and get tangled in your hair. Not. Bats locate prey and other objects by emitting calls and listening to the echoes that return from objects near them. These echoes are used to identify and locate objects, including prey which can be eaten. In this manner, the bat avoids flying into solid objects such as walls or humans.

• Bats carry rabies. False. While bats can contract rabies just like any other mammal, they are not “carriers”. Less than one half of one percent of bats contract the disease.

Typically, there are one to two cases of human rabies per year in the United States, most commonly coming from bats. A person is 25 times more likely to be hit by lightning than to contract rabies from a bat.

• Bat guano is unhealthy. It can be. Histoplasmosis, a type of lung infection, can be contracted by inhaling spores from the fungus Histoplasma capsulatum, which can be present in bat guano. However, the fungus does not grow in scattered bat droppings, as it requires humidity to flourish. Also, the fungus is not endemic in our area. Histoplasmosis occurs in the Midwestern states, but can be found elsewhere.

For their size, bats are the slowest-reproducing mammals on earth. Most bat species, including Tahoe’s little brown bat, have only one live birth per year. The pup at birth can be up to 25 percent of its mother’s weight, drinks milk from its mother’s breasts for one month, and is cared for in colonies of other mothers caring for pups. The male does not participate in rearing the young.

Breeding takes place in the fall, but the female delays fertilization until spring, when she will gather in a nursing colony with other mothers, perhaps returning to where she was born. The pups are born in the hot summer months, maturing in August, depending on the area.

A common bat at Lake Tahoe is the little brown bat, or little brown myotis. This bat weighs about half an ounce, its body is 2.5 to 4 inches long, with a wing span of up to 11 inches.

Bats mainly roost during the day, sleeping up to 19 hours daily, emerging at night to hunt, when insects are most prevalent.

The little brown myotis will eat about half its body weight per day. For example, if the bat only ate mosquitoes, that would be the equivalent of about 2,800 mosquitoes in one evening. That is a lot of insect control, and that is only one bat. Imagine what several bats can do to keep down the unwelcome insect population.

Tahoe Institute for Natural Science (tinsweb.org) offers bat classes for schools or organizations. Students will learn about bats that live in the Tahoe region through hands-on activities, exploring the lives and habits of these fascinating and beneficial flying mammals.

If you think you have bats in your belfry (attic or eaves), seek the advice of a professional. There are methods of exclusion that convince the bats to move away, without harming them. Even exclusion cannot be performed during the breeding months.

Bats, whether a federally protected or endangered species or not, are protected in California and Nevada. It is illegal to kill them, poison them, or “exclude” them from dwellings during the breeding months, which, in our area, is from May to August.

Better yet, next time you see a bat, think of the good work the tiny creature is doing to keep mosquitos at bay. Bats are our friends, and should be looked at with reverence, not revulsion.

Toree Warfield is an avid nature lover, and writes this column to teach and stimulate interest in the marvels that surround us. See the new website: saveourplanetearth.com to read columns and to find links to bird song recordings, additional photos and other content.