I was there shortly after Charlie last year and as the previous poster said, they all have 'houses' that they can go to each night. Each species has their own housing, and all are trained to go there to a different audible signal. This is one reason AK closes so early compared to the rest of the parks. They spend about two hours calling the animals into their shelters. In the event of storms, they call them in and leave them in, however, if an animal chooses not to, they said they let the animals ride out the storm in the open if that's what the animal wants.