Bats

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Bats are a large group of mammals, including 1116 known species spread throughout the world. Unlike flying squirrels, which actually glide, bats are considered the only true flying mammals. Bats have been falsely associated with witchcraft, sorcery, haunted houses, cemeteries and evil in general. Over the years they have been the subject of fables, folklore and myths. Unfortunately, many people still believe these myths today which serve as a basis for unfounded fear. In truth, bats are amazing, beneficial animals.

HOW DO I KNOW IF I HAVE BATS?

  • Homeowners usually know they have a bat infestation by observing bats roosting along the rafters inside a structure, under eaves, or behind window shutters.

  • You also may see bats entering or leaving your attic around sunset when they are going out to feed.

  • You may become suspicious if you hear a scratching noise in walls or ceiling during winter months.

  • If the noise is restricted to one area and it doesn’t sound “heavy” or is not “scampering” it likely is a hibernating bat.

  • Hibernating bats periodically will “wake up” from their hibernation and move around a bit. This is what you hear and it generally occurs during temperature “spikes.”

WHAT KIND OF BAT IS IT?

  • The two most common bats found where we live are big brown bats and little brown bats.

  • The bats are very similar in appearance and sometimes it is difficult to tell the difference between the two.

  • As its name suggests, big brown bats are relatively larger.

  • Big brown bats are about 4” in length and have a wing span of 12” to 14”.

  • Little brown bats are about 3” in length, and have a wingspan of 8” to 11”

  • Big brown bats weigh about 1/2 ounce.

  • Little brown bats weigh about 1/4 ounce.

  • Big brown bats have brown fur above, and paler fur below; while little brown bats have dark-brown, golden-brown, reddish, copper-colored or olive-brown fur on their back with lighter belly fur.

  • The wings of both the big brown bat and little brown bat are black and have no fur.

  • Their ears are small, rounded and black in color.

  • Their lips are fleshy and their nose is broad for the size of their face.

ARE BATS DANGEROUS?

  • Bats are potentially dangerous to humans, but not because “they want to suck your blood.”

  • Bats are a medical concern because their old droppings, or guano, may harbor a fungal organism that causes the lung disease Histoplasmosis.

  • Furthermore, bats can be associated with ectoparasites, such as bat bugs and bat ticks.

  • Also, a very small percentage of bats are infected with rabies. The rabies virus kills the bats, so they are rarely carriers of the disease. (Less than 10 people in the last 50 years have contracted rabies from bats.)

  • However, you should never approach a bat that is on the ground, unable to fly, or behaving unusually, because it may be dying from the disease and would be a high risk if you handled it.

I HAVE BATS LOOSE IN THE HOUSE, WHAT DO I DO?

  • Try to isolate the bat in one room; put towels or a rug under the door, so it can’t crawl out.

  • If it’s summer, open a window and the bat should leave on its own.

  • Bats that are resting cannot just jump and fly like a bird. Bats must first go through a “warm-up” period, in which they stretch in an effort to get the blood flowing to the muscles in their wings.

  • Therefore if the bat is at rest, you should be able to walk up to it and put a coffee can or bucket over it so that you can trap it inside and remove it from the house.

CAN A BAT BE LOOSE IN MY HOUSE IN THE WINTER?

  • Bats hibernate during winter, so they are not active like they are in the summer.

  • More than likely, a bat has “woken” from its hibernation and crawled around and somehow found itself inside the house.

  • Simply trap and remove the bat to the outdoors.

  • A bat making it inside during the winter is usually a pretty good indication a colony exists within your walls or attic.

WHY ARE BATS IN MY HOUSE AND YARD?

  • Bats may be in your yard at dusk to hunt for food. This is a very good thing, since bats consume many flying insects each night.

  • Bats often follow the same flight plan each night for hunting, so bats could be returning from a roost in another location.

  • During hunting, bats will seek out protected areas (overhangs, soffits, above doors, etc.) during the night to rest, eat, and digest their food. Homeowner may see bat droppings below these areas.

  • Male and the female little brown bats do not roost together.

  • Female Little Brown Bats roost in attics, sheds, and barns during the summer as part of a large maternity colony. The heat helps the babies stay healthy.

  • Male little brown bats form much smaller colonies, and they tend to roost in the cavities of trees rather than buildings.

  • Big brown bats roost during the day in hollow trees, beneath loose tree bark, in the crevices of rocks, or in man-made structures such as attics, barns, old buildings, eaves, and window shutters.

  • Bats may find your attic or other structure to be a protected shelter in which to hibernate. Bats prefer hibernation places that are not too cold or too warm. If the bats are exposed to warm air during sunny days in the winter, they tend to move to cooler places to save energy. On the other hand, they will move to warmer places if exposed to especially cold winter air. During this process, people may hear squeaking or scratching sounds, as bats are moving between pipes, wires, insulation, and wall voids.

  • Big brown bats will generally hibernate in a different location than where they “roost” during the summer. But, they can hibernate in homes and various structures, such as barns and sheds.

  • Little brown bats on the other hand are known to abandon their roosting places in buildings and migrate to hibernate in groups inside caves or mines.

WHAT DO BATS EAT?

  • Big Brown Bats eat a variety of flying insects, especially flying beetles. They also eat moths, wasps, flies, stinkbugs, dragonflies, flying ants, mosquitos, lacewings, planthoppers, and leafhoppers -- all of which they capture while in flight.

  • Little brown bats prefer to eat insects that live in or on the water including midges and other aquatic insects, beetles, caddisflies, moths, mayflies, lacewings, and mosquitoes.

  • Bats can eat up to 1,200 mosquitoes in an hour

  • Bats eat half their body weight in insects per night. New mothers sometimes eat more than their own body weight in a single night.

  • Bats catch their prey while flying.

  • Bats use echolocation to hunt. This means they send out a high-frequency sound which bounces off objects, big and small. Then they can listen to the echoes and tell where things are, what size they are, and how they're moving. (Because of their sophisticated echolocation system, it is very unlikely a bat will ever get caught in your hair.)

  • Bats do not hunt for food in heavy rain or if the temperature gets too low.

  • Bats usually begin looking for food right after sunset.

  • Only three species of "vampire bats” live off the blood of animals. None of those species lives in the United States.

HOW DO BATS REPRODUCE?

  • Bats are flying mammals, not birds. Bats are not born from eggs like birds. Mothers give birth to babies called pups and feed them milk. The pups will stay with their mothers for one year.

  • Brown bats mate during the fall and winter before they go into hibernation, but the females store the sperm during hibernation and do not become pregnant until the spring.

  • In late May or early June female big brown bats give birth to one or two pups; little brown bat females have one pup per year.

  • Female brown bats form nursery colonies to rear young. The size of these colonies can vary, but usually fall within the range of 20 to 300 animals.

  • Brown bat mothers communicate with their pups with high-pitched squeaks.

  • A mother brown bat can identify her offspring based on scent and calls.

  • Brown bat pups are born blind, with no fur and completely depend on their mothers for nourishment. 

  • Brown bat pups eyes and ears open within hours of birth.

  • A pup is born with a full set of teeth

  • When the bat pups are 9.5 days old, they can control the temperature of their bodies.

  • Brown bat pups can hear as well as adults by the time they are 13 days old.

  • Young brown bats grow quickly and are able to fly in three to four weeks and catch insects on their own.

  • Male big brown bats do not participate in raising their pups.

  • A normal life span for a big brown bat is 18-20 years; while little brown bats typically live 6 to 7 years, though some live well beyond 10 years.

  • Baby brown bats are most likely to die during their first winter, since new pups have considerably less weight than adults do at the start of hibernation.

  • Males usually live longer than females.

30 INTERESTING FACTS ABOUT BATS:

  1. Bats account for nearly 25% of all mammals on the planet.

  2. More than 50% of the bat species in the U.S. are either in severe decline or on the endangered species list.

  3. Bats have a “functional” eye and are nor blind, but rely on their “sonar” to navigate during flight.

  4. Bats are very clean animals. Bats clean themselves and each other meticulously by licking and scratching for hours.

  5. Brown Bats catch insects with their wings.

  6. Big Brown Bats can fly up to 40 miles per hour.

  7. Bat droppings, called guano, are one of the richest fertilizers. Bat guano was once a big business. Guano was Texas's largest mineral export before oil!

  8. The world’s largest bat is the "flying fox" that lives on islands in the South Pacific. It has a wingspan of up to 6 feet.

  9. The Bracken Bat Cave in Texas is the largest known bat colony in the world. Over 20 million bats live in the cave, which is more bats than there are people living in Mumbai, India—one of the world’s largest cities. When the bats leave the cave, the group is so large that it looks like a huge storm on radar. The bats from the Bracken Bat Cave will eat over 200 tons of bugs every night.

  10. A small colony of bats can eat over one ton of insects in one year, or more than 600 million bugs.

  11. A single bat can eat more than 600 bugs in one hour, which is like a person eating 20 pizzas a night.

  12. Bats live on every continent except Antarctica. They are found almost as far north as the Arctic Circle and as far south as Argentina and the southern-most tip of South Africa.

  13. Scientists believe that bats first appeared 65-100 million years ago, the same time as the dinosaurs. The earliest known mega-bats lived 35 million years ago.

  14. In China and Japan, bats are symbols of happiness. In Chinese, the words for “bat” and “good fortune” are both pronounced “fu.”

  15. The story of Dracula originated in Eastern Europe; however, real vampire bats are found only in Central and South America.

  16. Scientist have been able to use the anticoagulation agent in vampire bat spit to treat human stroke victims and human heart patient victims

  17. Bats are not blind and, in fact, many bat species can see quite well; some species can even detect ultraviolet light.

  18. A bat’s echolocation is so finely tuned that it can detect objects as thin as a human hair.

  19. Bats can hear frequencies between 20 Hz and 120,000 Hz. Humans can hear between 20 Hz and 20,000 Hz. Dogs can hears between 40 Hz and 60,000 Hz.

  20. In most bat colonies, all the females birth their babies at the same time.

  21. Normally, bats hang with their heads pointed down. When females give birth, they reverse their position so the head is up.

  22. Mothers catch their newborn young in a special membrane between their legs.

  23. Wind turbines kill tens of thousands of North American bats every year. Rather than being struck by turbines, many bats appear to be killed by a sudden drop in air pressure near the spinning blades causing the tiny blood vessels in their delicate lungs explode.

  24. In 600 B.C., the Greek Aesop told a fable about a bat that borrowed money to start a business. The business failed and the bat hid during the day to avoid the people to whom it owed money. According to Aesop, that is why bats come out just at night.

  25. To sleep, bats hang upside down so they can fly away quickly if needed.

  26. For their body size, bats have larger brains than birds.

  27. Bat wings are made from finger bones covered by thin layers of skin. The wing membranes of a bat make up about 95% of its body surface area.

  28. A bat’s wing membrane helps the bat regulate body temperature, blood pressure, water balance, and gas exchange.

  29. Bats have small receptor cells called “merkel cells” on the surface of the wings that perform similarly to human fingertips.

  30. The merkel cells also have a single, tiny hair that enables the bat to feel the air flow over its wings and to make adjustments to the shape of their wings for more efficient flight.