While explosives may be discovered in surface areas, it is also possible to stumble onto explosives underground. Any disturbance may set off explosives after decades of sitting in an abandoned mine. Though many old mines in other parts of the country may have snakes, scorpions, and spiders, in Michigan it is possible to stir up a black bear residing in an old adit or mine opening. Bears are known to occupy some adits. You cannot predict what a bear will do in a confined space.
Bats usually occupy abandoned mines.
Bats will try to avoid you, but they may startle you. MAZE OF A MINE Underground areas, such as adits, drifts and levels are often in a maze of passages. Persons have died in the maze of an old mine from exhaustion, thirst, hunger, and exposure as well as from slips and falls. Some mines in Michigan have many miles of passages. Do not cross fences.