Chino the Capuchin monkey in South Africa appears to love the crushing sounds of leaves, particularly when it is a group activity.
So, Chino teaches a human participant how to crush the leaves. She put pieces of leaves in a person’s hand and then it makes you close your hand in a fist, so it can hear the crushing sounds from inside.
Pretty smart monkey, huh! She knows exactly what it likes and how to get it too.