The Little Dutch Wooden Sound Puzzle Little Farmoffers7 animals and a tractor with sounds that promote hand-eye coordination and stimulate your little one's vocabulary. When you place the animal back in its correct place, you will hear a matching sound. The puzzle contains light-activated sensors - use in bright light for the best results. Make sure the switch is ON to activate the sound function. Sensors can be accidentally activated by direct sunlight, so always turn them off when not in use. (Batteries (2 x AAA) not included.)