While we were staying in a really great cabin down off of Matapalo Beach on the Oso Peninsula in Costa Rica (Sueño Verde), we were often visited by families of Capuchin monkeys who would go foraging for insects and coconuts in the trees right around our bungalow. They would meticulously climb through each coconut tree and check each palm frond from the top side to the bottom side. I was able to time it and catch one as he was peeking through the fronds to look underneath.