Although bats have a bad reputation, these nocturnal flying mammals contribute generously to Utah's ecosystem. Surprisingly, bats can eat 30 percent to 100 percent of their body weight in insects each night, ranging from crop-ruining beetles to scorpions.
Bats make up 20 percent of all mammals, with more than 950 species worldwide. Only three of these species actually feed on blood and are not among the 18 species living in Utah.
During this time of year, Utah will see a small growth in the bat population. Here are some facts that might come in handy, especially if you find them roosting in your neighborhood.
What they are
Mammals capable of flight
Some species can make a right-angle turn at 40 miles per hour.
Sky- and land-dwellers
Their wings fold, allowing them to crawl and hop on the ground.
Hibernators and migrators
Some species migrate with birds.
Flying foxes or fruit bats
These larger bats can have a wingspan of 6 feet. They eat fruit and pollen. They are found in Africa, Asia and Australia, and are of the suborder species Megachiroptera.
Microchiroptera (includes Utah bats)
These bats are smaller, have pug-like noses and eat insects.
Where they roost
Most bats nurse their young together in maternity colonies
Utah bats roost in trees, caves, rock crevices, attics, buildings, bridges and barns. Some bats colonize while others roam in solitude. To encourage roosting, bat houses can be installed in enthusiasts' yards.
What they eat
Utah bats are carnivores
They eat beetles, moths, mosquitoes, flies, crickets, scorpions and other pests.
How they eat
Bats use high-frequency sound, or echolocation, along with eyesight, to navigate and detect prey.
1. First the bat sends out ultrasonic squeaks through its mouth.
2. The squeaks' sound waves bounce off environmental objects and return to the bat as echoes.
3. The echoes are then computed by the bat's brain to form a "sound picture," and the bat understands its environment. Most echolocation is inaudible to humans.
SOURCE: "Eyewitness Books: Mammals"
Myths about bats
All bats have rabies
Rabies occurs in less than 1 percent of bats. Humans can contract the virus, and it is fatal if left untreated.
Bats will suck your blood
Mostly birds, horses and cattle fall victim to vampire bats in Mexico, Central America and South America. These bats don't "suck" blood but make small cuts with their teeth.
Bats are blind
Bats have eyesight but are colorblind. They also use echolocation to "see" their environment.
Problems they cause
Bats can transmit diseases to humans
Histoplasmosis, which primarily affects the lungs, is transmitted through bat droppings. Rabies, which affects the nervous system, is transmitted through a bite. Rabid bats behave strangely, such as being active during the day.
Bats occupy homes
To determine where bats may enter your home, check for gaps in siding and around chimneys.
All bats are protected by Utah law
It is illegal to intentionally kill a bat. The Environ-mental Protection Agency permits one chemical (naphthalene) as an indoor repellent.
For more information, visit Bat Conservation International's Web site at www.batcon.org
How bat and bird wings compare
A bat's "thumb" extends upward like a small claw.
A bat can move its wing like a hand.
Bat wings are made of a delicate, elastic skin.
A bird's wing structure is rigid. Most movement occurs at the point where the bones connect to the body.
Most caves in Utah are gated or unaccessible to the public so roosting bats remain undisturbed. During the late summer, bats can usually be seen at Tibble Fork Reservoir, near Timpanogos Cave in American Fork Canyon.
Visitors view the formations in the White Rocks Cave near Vernal. The photo is part of an exhibit at the Utah Museum of Natural History.
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The Utah Museum of Natural History explores caves in two exhibits that run Saturday through Oct. 2.
At Hogle Zoo
The zoo houses two kinds of bats: the Short-tailed Leaf-nosed Bat, shown above, and the Indian Flying Fox.
SOURCES: Bat Conservation International (www.batcon.org); "Eyewitness books: Mammals"; U.S. Fish & Wildlife Services; www.sibr.com/mammals/M026.html; dwrcdc.nr.utah.gov; www.tpwd.state.tx.us; Center for Disease Control and Prevention (www.cdc.gov); Colorado Division of Wildlife; Utah State University Extension Wildlife Damage Management Series; www.howstuffworks.com