Award-winning photographer David Slater was following a pack of macaques through the Indonesian jungle when one of the monkeys took his camera and began snapping photos. The primate seemed to know what it was doing, even smiling for one photo. “They were quite mischievous jumping all over my equipment, and it looked like they were already posing for the camera when one hit the button,” Slater explains. "The sound got his attention and he kept pressing it. At first it scared the rest of them away but they soon came back—it was amazing to watch. He must have taken hundreds of pictures by the time I got my camera back, but not very many were in focus.” Slater spent three days with the crested black macaques, which are critically endangered.