This is one of my favorite photos from a recent trip to Costa Rica.  It was taken in Manuel Antonio National Park.  I had been chasing Iguanas, raccoons, lizards and hermit crabs up and down the beach all morning.  Every so often a roving band of White Faced Capuchin Monkeys would come by pillaging everything they could get their hands on.  It was quite a site.  Their rapid movement and the low light conditions under the trees made getting a decent exposure difficult.  Around mid-afternoon the monkey were worn out and they all headed for a couple of trees to rest in.  I'll bet I took close to 200 pictures of the monkeys but this one stood out the most.  The eyes and facial expression are worth a thousand words.