http://science.howstuffworks.com/life/biology-fields/cave-biology3.ht

https://mostateparks.com/page/55121/food-chains-and-pyramids

​http://www.blm.gov/wo/st/en/res/Education_in_BLM/Learning_Landscapes/For_Teachers/science_and_children/caves/index/caves_bats.html