Apart from silver or lead, the former mines of the Sainte-Marie-aux-Mines region are also home to a fragile fauna of salamanders, spiders, and bats. Four species of bats live in the galleries of the Tellure mining park, including the small Horseshoe bat and the Great Murin. They seek its underground cavities to hibernate from December to March. Reptiles, such as the smooth snake, also dwell in the mines, whose temperatures average 50° F (10° C) throughout the year.