Penguins swim in the Detroit Zoo's new Polk Penguin Conservation Center, Wednesday, April 13, 2016, in Royal Oak, Mich. The new penguin habitat that the zoo calls the world's largest such facility offers its 80-plus residents new rocks for climbing, waves, snow and better ice conditions, while allowing visitors to come nose-to-beak with the stately birds. (Photo by Carlos Osorio/AP Photo)
