Showering rain and spraying eggs makes babies love bathing. Space exploration and buoyancy perception enable babies to imperceptibly learn physical knowledge while playing. They can fully immerse duck eggs in water and automatically float when the eggshell is filled with water. The duckling's head will pop out, and the eggs will be taken from the water. When the water is less spilled from the bottom of the eggshell, the egg shell will be retracted.