Caves
A cave, often though of as just a hole in the Earth, is really defined
as: "a hollow or natural passage under or into the Earth, especially one with an opening
to the surface."
There are many different types kinds of caves. One of them is called a solution cave.
A solution cave is the most common type of cave around. They are formed out of limestone that has been dissolved by acidic water, and they can contain numerous stalactites. Stalactites are those things that look like huge icicles hanging from the ceilings of caves. Solution caves can also have a lot of stalagmites. Stalagmites are pretty much the same as stalactites but they point upward from the floors of solution caves.
Another type of cave formation is the lava tube cave. This cave is formed by flowing lava. Then there are sea caves carved by the power of the oceans. These may be dangerous to explore because of their jagged rocks. Lastly, there are erosional caves. These have been formed by wind or water erosion of rocks, such as granite or sandstone, or even ice.
Let’s look at a real cave with organisms inside. Caves, whether you know it or not, are pretty convenient and cool places for a lot of animals and other organisms to live in. Take the Missouri Caves. In these caves the temperature usually remains constant, which is a good thing for the organisms that live inside. It varies from 55 to 58 degrees Fahrenheit. Near the entrance of these caves, birds dwell but almost never fly inside. They use the cave entrance as protection from harsh weather.
Deeper in the cave is where there is no light there is a place which biospeleologists call the twilight zone. Sound creepy enough? Not much vegetation lives deep in a cave due to its lack of sunlight.
What is able to live in the darkness of caves? When people think of caves, bats usually come to mind. Caves are important habitats for bats. Bats don’t mind the dark. Some bats are able to see very well in the dark. And some bats don’t need any light at all in order to “see”. These bats do an amazing thing called echolocate. To do this, they send special sound waves out into the world around them. When the sound waves hit objects in the environment, they bounce back to the bat as echoes. These echoes give the bats information about what is there (whether it’s a wall to avoid flying into or an insect to eat!).
Caves are important habitats for bats and other creatures, and some people are hard at work to protect these “twilight zones” and there amazing animals that live there.
