Mother duck said, ‘Quack, quack, quack, quack’, but Bill the Duck could only rattle back. Charlie the Chicken told Bill the noise was caused by eating too many worms but worms are squishy, so Bill is not so sure. He quite likes the rattling sound & yearns to share it with a little playmate who can shake, rattle & roll.
Unlike squeakers, which are short-lived & unintuitive for babies to use without assistance, the sound the rattle makes when babies hold or move it stimulates action-reaction learning, providing babies & toddlers with an instant reward & helping them understand cause & effect.