Flying Bug Zappers
Here’s the first of a series of posts (“Mammal of the Month”) I’ll be doing about various biological topics related to mammals. Since it’s October, and everyone is thinking about Halloween (and Christmas, if you’ve been in a store recently), I decided to share some information about bats, which are often featured in Halloween lore and scary decorations. Rather than fear bats, I would argue that you should appreciate them for the ecological services they provide.
Most bats here in Virginia are fairly small; many weigh less than ¾ of an ounce (about 21 grams). As a result, they have very high metabolic rates, and they need to eat large amounts of food to survive. All bats in Virginia feed on insects. They are essentially flying bug zappers.
Some of their insect prey (such as gnats) merely annoy us, but others (such as mosquitoes) can transmit diseases that infect people (West Nile virus), their pets (heartworms), and their livestock (equine encephalitis). In fact, a single bat can eat as many as 600 mosquitoes in an hour. Multiply that number by several tens of thousands of bats, each of which forages several hours each night during the summer, and the numbers quickly become astronomical. Bats that live in Virginia also prey on other insects (such as June beetles and green stink bugs) that damage lawns and a variety of crops, including alfalfa, soybeans, cotton, and peaches.
In sum, these animals do the work of hundreds, if not thousands, of pounds of chemical insecticides. And they do it for free.