Use a plastic bag and water to demonstrate how webbed feet work.

What You Need

• Picture of a duck’s webbed foot
• Plastic sandwich bag
• Rubber band
• Toys that float
• Small portable tub
• Water

What You Do

1. Look at a Webbed Foot
   Show your child a picture of a duck’s webbed foot. Explain that the flaps of skin between the duck’s toes form what we call a webbed foot.
2. Experiment with the Plastic Bag
   • Place a plastic bag over one of your child’s hands. Secure the bag in place with a loosely fitting rubber band.
   • Ask your child: How is the hand that is covered with a plastic bag like a webbed foot? (Water cannot pass between the fingers of this hand, just as water cannot pass between the toes of a webbed foot.)

   

3. Experiment with the Toys
   Put two toys in the water. Then ask your child to do the following:
   • Put both hands in the water behind the toys. Spread your fingers apart on both hands and move them slowly back and forth.
   • Now try to move the toys by pushing the water with your hands.
4. Talk About What You Learned
   Ask your child:
   • Which hand pushed the toys farther—the “webbed” hand or the “non-webbed” hand? (Webbed hand)
   • What type of foot do you think would push a duck better through water—a webbed foot or a non-webbed foot? (Webbed foot)
   • For an older child: How do webbed feet help ducks swim better? (No water can pass through gaps between the toes. This gives the feet more force per stroke against the water.)