Some foods, however, are only availableto those who have skilful hands and sharp intelligence.On the coast of Costa Rica, among the mangroves,live some of the most intelligent monkeysin the whole of the Americas.White-faced capuchins.They too have learnt to work the tides.They are after clams.But capuchins are quite smalland don't have the brawn to open such shellfish.But they do have the brain,and they've devised an ingenious way to solve the problem.They hammer the clams.They are not trying to crack the shells,all this pounding and rolling has another purpose,to tire the muscle with which the clam is holding itself shut.
