A: There are 10 bat species that are said to be common in Colorado with almost 1,000 species found worldwide. The Big Brown, Hoary, and Little Brown bats are probably the most abundant in Colorado. Bats are the only mammals capable of flight. They make up a quarter of all mammal species, and have the second highest number of species of all mammal families - the rodent family is the largest.Little Brown bats, while hibernating, can reduce their heart rate to 20 beats per minute and can stop breathing for 48 minutes at a time. They can hibernate for more than seven months if left undisturbed. Some bats can lower their body temperature to just a few degrees above freezing while hibernating.A single Little Brown bat can catch hundreds of mosquitoes in an evening. A nursing Little Brown bat mother can eat more than her body weight nightly (up to 4,500 insects). As the primary predators of night-flying insects, bats play a vital role in maintaining the balance of nature. Bats species that will live in bat houses often eat insects that could damage crops.Providing bat houses can help build the populations of many valuable bat species including Little Brown and Big Brown bats. Bat houses provide places for bats to roost, hibernate and raise their young. The majority of bats that use bat houses are females who utilize them as nurseries for their young. Bats find houses by sight. If a house in the proper location, meets the requirements, and is needed, the bats will move in on their own.Bats are not carriers of rabies, and thus do not survive the disease nor harbor or spread it around for years like a true carrier would. Only about 0.5% of bats ever contract rabies, and usually only bite people in self-defense. Rabies in humans is very rare in the U.S. There are usually only one to two human cases per year. In the northern two-thirds of the U.S. and Canada, most bats migrate south in the winter. Most bats that inhabit bat houses will spend the winter in caves or mines.Fruit bats, like the Flying Fox, are responsible for scattering up to 95% of the seeds needed for new trees in tropical rain forests. Plants that are pollinated by bats only bloom at night. Bats are the main pollinator throughout most of the tropics and in many desert habitats. Many of the plants found in these areas would not survive without bats. Plants that are dependent upon the fruit bats include bananas, breadfruit, carob, avocados, dates, figs, peaches, cloves, mangos, cashew nuts and agaves.Bats have existed for almost 50 million years and the fossil remains of the earliest bats differ little from the skeletons of modern bats. Bracken Cave in Texas contains the largest bat colony in the world. This cave is home to as many as 20 million Mexican Free-tailed bats each summer. The largest urban bat colony is under the Congress Avenue Bridge in Austin, Texas. The bridge is home to about 1.5 million Mexican Free-tail bats...roughly one bat for every human resident of the city.Bats are not blind and have decent eyesight, but they rely mostly on their incredible sonar ability to find their way. By listening to the echoes of the high-pitched sounds that they make, bats are able to judge the size, distance and movements of everything in their path.Local bird expert Larry Collins owns Wild Birds Unlimited, 2454 Hwy. 6&50, which caters to folks who want the best backyard birdfeeding experience possible. Email your birdfeeding and birding questions to email@example.com and he'll answer them in his bi-weekly Q&A column in the Free Press.