At the end of my hike in Penang National Park, Malaysia, I came across a troop of monkeys on the side of the path. At first they got ready to run from me, but when I looked around and acted uninterested they became more comfortable. Eventually, this crab-eating macaque laid down on her back to have the male continue grooming her belly. I couldn't believe I got to see this from wild monkeys, and continued snapping away. This photo was taken on a Canon T6i (750D) with a 75-300mm Canon lens.