Texas Parks & Wildlife has a page of background information for teachers on caves and caverns: http://tpwd.texas.gov/education/resources/keep-texas-wild/cave-creatures/background-for-teachers-cave-or-cavern
They also published a colorful 4-page magazine issue with cave resources for kids – Underground Connection: Amazing Animal Communities Inhabit Texas Caves (PDF).
This information is applicable to all caves, not just in Texas. Here’s a map:
Summer is a great time to explore a cool cave near you!