Leigh Stuemke, refuge technician for the Fort Worth Nature Center, talked Jan. 22, 2007, to the Cross Timbers Master Naturalists about bats. Her presentation was titled, “The Graveyard Shift: employees numbering in the millions!”

notes by Brian Builta, who was tired that night from a long day of driving, so he may have muddled a few facts (sorry Leigh!)

Bats suffer from bad public relations in the United States, and they don't fare too well across Europe, either. The Mayans saw bats as guardians of the Underworld. The Chinese associate bats with happiness while Egyptians link bats to images of good health.

Leigh stressed, right off the bat, that bats are not blind, they do not suck blood, they will not attack your hair, they don't all carry rabies, they are not rodents, and they are not just a really cool transportation system for vampires.

Bats provide a major service to humans because they devour a massive number of insects each night, making them nature's greatest insecticide, and they are found all over the planet, except in extreme locations like the North Pole, the Antarctic and the Vatican.

Even vampire bats, which comprise only three of the more than 1,100 bat species, are not as bad as their reputation. “They don't suck blood,” Leigh said. “They just drink a little.” Vampire bats make a small slit in the unsuspecting creature they've chosen as a restaurant, and then drink one or two teaspoons of blood. “Most animals don't even know they've been bitten.” Vampire bats, Leigh said, actually adopt orphaned bats, but nobody ever puts that in a movie.

“Bats will actually lick birds,” Marshall Fox blurted out. “They are really not bad at all.” Leigh nodded her head, which I took as an acknowledgement that bats indeed are bird lickers.

When it comes to bats, Leigh said, Franklin Delano Roosevelt was right: “The only thing we have to fear is fear itself.”

Bats are mammals. That's right, just like you and me. In fact, one out of every four mammals on the planet is a bat. They are the only mammals that can fly. [Flying squirrels don't count; they glide.] Leigh had us raise our hands in front of our faces and then showed a picture of a bat wing, which is basically a hand with webbing between the fingers. Made us all feel a little batty.

Bats are broken into two categories: megachiroptera and microchiroptera. Chiroptera means “hand winged,” Leigh said. She said a bunch of other things about mega- and microchiroptera, but quite frankly, she talks fast. Leigh is from Wisconsin and was educated in Minnesota, the combination of which apparently leads to fast talking. But mega means big and micro means small and I already told you what chiroptera means, so draw your own conclusions.

There are plenty of cool bat facts:

•  Bats hang upside-down because they cannot take off from the ground. They simply drop and start flapping like mad.

•  When bats are hanging, they are at rest. They must engage their muscles to release their grasp.

•  Bats have a tail membrane they use for maneuvering during flight, catching babies during birth, and as a snuggly blanket.

•  Many bats navigate by echolocation. They send out sound waves that bounce off stuff and return to the bat, thus revealing the location of trees, insects, hawks, and humans standing open-mouthed and screaming.

•  Bats can communicate on the same high frequency as dolphins, but they cannot swim.

•  Many female bats birth only one pup at a time, making them the slowest reproductive mammals on earth. [Does that make them slower than humans?]

•  At the high end, bats can live 30-35 years.

Leigh said bat pups at birth are often 20 to 30 percent of the mother's weight, which is equivalent to a 100-pound woman giving birth to a 20 to 30-pound baby. This statement inspired groans among female naturalists for some reason.

Like humans, different bats eat different foods, including frogs, fish, fruit, pollen and gobs and gobs and gobs of insects. They drink “on the wing,” which means they don't stop flying to drink. In one hour, a bat will eat 1,000 mosquito-sized insects. In one night, a bat will eat one quarter to one half his or her body weight. Leigh gave other bat eating statistics, but at this point she began talking fast again and her figures started jumbling in my head. The basic gist, though, was that bats eat a boatload of insects [Note: ‘boatload' is not a scientific measurement.]. For example, in central Texas, Mexican free-tailed bats eat 200 tons of insects each night. Thank you, bats.

Snakes and raptors think bats are delicious.

Bats live in caves, of course, but they also live in buildings, under bridges, in tree foliage and hollows and empty woodpecker holes, in abandoned mines and burrows, and in your house if you have holes a 1/4-inch wide or more along your roofline.

Leigh spent a lot of time talking about bats and health concerns, primarily rabies. “All mammals are susceptible to rabies,” Leigh pointed out. “Only one half of one percent of bats have rabies.” She did warn, however, not to handle grounded bats. “They are very docile,” Leigh said. “When infected with rabies, they do not attack or foam at the mouth.” She also mentioned that while individual bats are infected with rabies, there has never been a proven outbreak of rabies within a bat colony.

Leigh also talked about histoplasmosis (an airborne fungal disease) and the West Nile virus. In extreme situations, like if you wander into a cave with a million bats and guano up to your armpits, you could contract histoplasmosis just by breathing, but that is a rare case. Bats do not transport West Nile virus.

The main reason for population decline among bats, besides being eaten by snakes and raptors of course, is humans, Leigh said. Sometimes hoodlums will torch bats in caves, perhaps out of fear, but most probably out of social dysfunction. There are lots of studies being conducted about wind turbines and their affect on bat populations.

Sometimes people harm bats out of fear and plain ignorance. We do, as it turns out, share the planet with bats, so it behooves us to learn more about them.

If a bat flies uninvited into your house, Leigh said, “please do not go after it with a tennis racket. Just close all doors and open a window. Bats seek darkness and will fly out [Unless, of course, more bats fly in.]. Do not use mothballs, Leigh warned. “The amount of mothballs it takes to drive out bats is lethal to you.” And that's good advice to have. Thanks, Leigh.

If you would like to learn more about bats, read a book. Leigh said Bat Conservation International has a good book on bats. If you are interested in building a bat habitat, visit www.batcon.org . If you would like to see bats in action here in Texas, Leigh recommends three spots:

•  Bat World in Mineral Wells ( www.batworld.org )

•  Congress Avenue bridge in Austin, in spring and summer, home to the largest urban bat colony in North America

•  Bracken Cave, in central Texas