Wildlife: The cave has three features vital to the wildlife living in it. The temperature and level of humidity are constant through the year, and, except near the entrance, it is always dark. At the cave entrance, green plants grow in the dim light, and where the cave is wet there may be mosses ad ferns. Some moths winter in the cave entrances. Insects, mammals, and birds wander in and make their homes there. Deep in the cave, no plants grow in the darkness, so no food exists for plant eating animals. microscopic bacteria and fungi live on the droppings of bats or birds, or no material washed in by streams. These organisms form food for flies, water shrimp, and millipedes, which in turn become food for other animals.

Food is scarce, so animals save energy when possible. They grow and move slowly and lay few eggs. Some lose the larval ( early form of an immature animal) stage of their life cycle to conserve above.  Cave animals are often paler then related species above ground. They are often almost blind and find their way in the dark with long antennae and a keen sense of smell. Many cave species cannot tolerate exposure to light.

Prehistoric Animals: Caves provide evidence about people and amnaimls that lived  durnig the last Ice Age. Explorers have found remains of Ice Age hyenas, reindeer, woolly mammoths, bears, bison, and cave lions, which were twice as big as the mordern lion. Some animals strayed into caves or fell through their roofs and died. Others were killed and then dragged in by preditors, including early man. Caves also contain tools that were made of animal bones by early humans. These, together with bone carvings and cave paintings, give us clues to early human life.

Bats: Bats are usually the largest animals living in caves. They roost there in winter in the darkness of its depts. They will not fly into a cave uintil the temperature and humidity (dampness) are just right. Bats often return weac year to the same crevice in the darkness. Their droppings, or guana, provide food the creatures living below and introdue important nutrients into the cave food chain. Bats see in the dark by bouncing high pitched sounds off the walls to form a "sound picture."  This type of navigation is echolocation.

Cave Formation: Many natural caves are formed from a rock known as limestone. This rock slowly dissolved in rainwater, which is a weak acid. When water drains through the limestone, it causes small cracks. THese cracks widen each time more water enters, breaking off peices of stone and washing them away. The water forms small streams underground. The combined effect of the water and the losose stones it carries carves out caves or caverns (larger caves) in the rock.

In some cave sites, the entrance is a shaft that runs from from a hole in the ground down to the cave. Elsewhere, where rocks lie at different angles, entry is easier. Some caves are quite small, while others form vast underground chambers or a series of connected caves. Many have water running through them. Sometimes the river has rerouted to a lower level, leaving the cave system dry. Early humans inhabited these dry caves.

Stalactites and stalagmites: The water that drisp through the roof of the cave contains a mineral, called calcite, that it picks up as it passes through the limestone. As the water evaporates, deposits of calcite left on the cave ceiling gradually form stalactites. Similarly, stalagmites frow on the floor below as water contained calcaite drips onto it. Both feathures take many hundreds of years to form and are very fragile and easily damaged.

Threats to cave Wildlife: The few animals that live successfully in caves die easily if their delicate habitat is disturbed. Quarrying for limestone destroys many caves, but some are now protected to prevent this. Spelunkers (cave explorers) who accidentally step on the raised edges of a pool break them down and allow the water to drain out, killing all the tiny creatures that live there. Some cave visitors pollute the delicate pools when they leave behind used flashlight batteries and other trash.

These days cave exporing clubs have strict rules to try to mimumize the disturbance to the caves. Members are often scientist doing research. Bats are easlily disturbed as they roost. Lights, noise, and the increased warmth from people bodies many awaken them from hibernations. An entre bat colony can dies in this way. many bat caves are now closed off with bars, which keep people out but allow bats continued access.

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