What is Cave?
[[File:St moré cave.jpg|thumb|right|View from a cave, looking out. This cave is in [[France]]]] [[File:Lechuguilla Cave Pearlsian Gulf.jpg|thumb|Cave in New Mexico]] [[File:Cuevas de Acsibi, Salta (Argentina).jpg|thumb|Cave of Acsibi, [[Argentina]]]] A '''cave''' is a natural underground hollow space. They can have narrow passageways (corridors) and chambers (caverns). They are usually formed when underground acidic (sour) water wears away softer stones, such as limestone. Only the hard rock, such as granite, is left. Caves can also be formed during natural catastrophes, such as [[earthquake]]s, or by ice and glaciers. Caves can have formations in them such as [[stalagmite]]s and [[stalactite]]s. These are made over thousands of years by water dripping and leaving [[mineral]] deposits. Many creatures live in the entrance areas of caves, for example [[snakes]], [[mice]], [[spiders]] & [[porcupines]]. Only a few animals are found deep in caves. [[Bats]] often live in caves. Another common creature found in caves is cave crickets. In the past, people lived in caves. People used to live in many European caves in the [[Stone Age]]. Caves still provide [[shelter]] for trekkers. Some caves have beautiful paintings on the walls. People who explore caves are called cavers or speleologists. (The study of caves is called '''speleology'''.) They go into caves for fun, exercise and to see the different formations. This can be a dangerous sport because caves sometimes have deep holes. Cavers also have to climb and crawl through the passages. Cavers usually go into caves with four or more people. Each person has 2 or 3 light sources. One light is attached to each [[helmet]]. People go into caves to try and explore more about the world. [[Category:Caves| ]]