Leaves fall from trees in autumn. They drop to the ground. Some leaves fall on water. They do not sink. They float. Why do leaves float?
Look closely at a leaf. A leaf has many tiny holes. People cannot see these holes without a microscope. These tiny holes are called stomata. Air gets trapped inside these holes. Air is light. Water is heavy. Light things float on heavy things. The trapped air helps the leaf stay on top of the water.
Leaves also have a special top layer. It is a thin, waxy skin. This skin keeps water out. If water gets inside the leaf, the leaf gets heavy. A heavy leaf sinks. The waxy skin stops water from going in. The leaf stays dry and light.
Trees need leaves to catch sunlight. In autumn, trees stop feeding the leaves. The leaves turn brown and red. They dry out and fall off the branches. Even when dead, the leaf structure stays the same. The tiny air pockets remain inside. That is why dry autumn leaves still float.
Ponds and rivers look pretty with floating leaves. Little bugs use floating leaves as boats. Frogs jump on them. Next time you see a leaf on a puddle, look at it. It is a tiny boat made by nature.
What color leaf is your favorite?