Abandoned coal mines can be dangerous for people because of sudden ceiling collapses and oxygen-deficient air, but they can also provide valuable wildlife habitat. The old barricade over the entrance to the Lusk Coal Mine prevented bats from entering, so on April 29, 2000, the entrance was permanently gated to protect both visitors and bats. Volunteers from the Indiana Karst Conservancy carried steel bars weighing as much as 300 pounds down the steep hill, cut them to size with a cutting torch, and welded them into place. The gate was designed to let bats fly freely in and out so they could reach the protected roosting habitat inside. Bats play a vital role in the ecosystem by consuming vast numbers of insects that are among the costliest agricultural and forest pests, yet bat populations are declining at an alarming rate because of habitat loss.