Stalactites grow from the ceiling down. Remember "stalactites stick tight to the ceiling."

Stalagmites grow from the floor up. The base of a stalagmite is thicker than the top.

A column is formed when a stalactite meets a stalagmite.

A curtain is formed when water flows down a sloped ceiling. A thin layer of rock is formed. If you get a chance to shine light through a curtain, you can see through it!

No sunlight reaches the interior of a cave. Without light, no plants can exist inside the cave. Compared to above ground, little food is available in a cave. Cave animals are small, cold-blooded and usually colorless. These animals require little food. Cave animals usually have poor eyesight. To help them find food in the dark, they have well developed senses of taste, smell and touch.

A troglobite (TROG-lo-bite) is a cave animal that spends its entire life in a cave. The blind cavefish and amphipod are troglobites. Some animals visit caves but also spend time above ground. These organisms are called trogloxenes (TROG-lo-zeens). Some bats and frogs are trogloxenes.

Because caves are formed by water, pollution of surface and ground water can lead to destruction of the cave and organisms that live in it.

Check out a library book and read about caves. An Internet site that can provide more information about this habitat and cave organisms can be found at :
Illinois caves http://www.inhs.uiuc/edu/~sjtaylor/cave/biospeleol.html .