Bat

Bats are the flying mammals that make up the order Chiroptera. Though by many it is believed that bats are harmful to humans, they feed mostly on insects and fruit, with the exception of the vampire bat which drinks blood from other mammals.

Anatomy
A bat's wings are mainly constructed of long fingers and skin that covers them. Their fingers are highly flexible because they do not contain as much calcium as most other mammals do. Another reason their fingers are so flexible is because the circular "cross-section" found on humans is flat on bats. The thin layer of skin covering the fingers is made mostly from membrane cells, rather than as birds have, feathers. This enables them to fly and maneuver faster than most birds.

As with other mammals, a bat's veins contains "valves" that allow the blood to flow only in one direction. This disables the blood from flowing backwards away from the heart. The blood, instead, goes through a cycle, passing through the arteries, which takes the blood away from the heart, and to the veins, which takes the blood back to the heart.

The teeth that bats possess are sharp. Their main use is to enable the bats to pierce the hard exoskeleton of insects or even the skin of fruits.

Reproduction
Female bats only produce about one "pup" every year. Generally, they do so with other female bats in a cave, creating a colony. Though there are many pups in the colony at this point, the mother can still find her pup among them. While mothers leave the cave, the young pups are left in the "roost." However, they may grab on to their mother and leave with her. This only happens when they are small enough for the mother to carry. Female bats are the only ones to care for their young, as the male bats discontinue the "partnership."

The two different suborders of bats - Microbats (Microchiropterans) and Megabats (Megochiropterans) - achieve the ability to fly at separate times in their lives. The microbats learn to fly in about 6 to 8 weeks after they are born, but the megabats, however, don't learn to fly until about 4 months after birth. This is because their wings are much larger in size than the microbats.

At the age of two, bats become mature enough to reproduce.

Ecology
Bats are nocturnal, meaning they are most active at night. At this time, they can be found searching for prey. There are two separate types of bats which use very different senses to be mobile and locate food. One of these is Megabats. These include large bats which use the sense of smell to find their main source of food - fruit. The most well-known bat in this group is the fruit bat. The second of these is the Microbats. Though these bats have sight, it is not the sense they use the most. Instead, they use their most effective sense - hearing - to locate prey and get around. By creating high-pitched sounds, they are able to determine where its prey is by the amount of time it takes for the sounds and vibrations to return. The echoes which reach their ears allow them to locate prey without the use of eyes. Among this group of bats is the vampire bat. It uses two of its sharp front teeth to pierce the skin of its prey and drink the blood. This is the only bat that drinks animal blood.

Bats travel in two different ways - fusion and fission. Fusion occurs when bats travel together in one area. Fission is when the bats break up into separate groups and head in different directions. To communicate, they use a series of high-pitched noises, too high for the human ear to hear. The sounds they produce have different meanings. The "herding buzz" is a call that uses many "clicks" produced by males trying to protect their territory. Another important call that was studied by scientists was the "Parturition distress call." This call is used when the female bats are having problems while giving birth.

Bats are carriers of certain diseases such as rabies and SARS. Though it has been assumed that only about .5% of these animals will pass on a disease, there is still the chance that these animals could bite if being handled.

Other facts
It has been said that bats are blind. However, this is not so. Bats have generally good vision, but their best sense is hearing and smelling.

The only flying mammals in the world are bats. Though many believe that flying squirrels are actually flying, they are only "gliding."

Evolution and Bats
Bats represent yet another challenge to evolution. The oldest known fossil of a bat was fully-formed. In fact, the entire appearance of bats is an "evolutionary enigma" because they appear so suddenly in the fossil record. Even though evolutionists believe bats evolved from non-flying mammal ancestors, there is no fossil evidence to suggest this. Nancy Simmons, with the American Museum of Natural History, admits "We've never had an adequate explanation" for the sudden appearance of bats." In a classic case of evolution explaining lack of evidence, evolutionists have reasoned away the lack of transitional forms in bat evolution by suggesting that the features of bats evolved very rapidly.

In another finding that disagrees with evolution, researchers studying bats found that in the family of bats, "Morphological evidence does not agree with molecular evidence." This contradicts evolutionary assumptions that common descent and morphology will show common molecular structure.