This is a fantastic book! As do ALL of Eric Carle's books, this gem has beautiful, colourful, engaging pictures. Each animal has a sentence about it, and when you press the button, it says the name of the animal, then the sound it makes. You'll recognize several of the pictures as they are borrowed from his other books, which I think is great. The turtle, rabbit, butterfly and caterpillar (yes, that one!) have a little tune or sound effect -- the rabbit one is a 'boing, boing' bouncing sort of sound, the turtle's is a low, slow melody, and the butterfly and caterpillar's are bright upbeat little tunes.