Book 17, Question 54
How Do Tree Frogs Stick to Leaves?
Tree frogs have sticky toe pads that cling to leaves, even wet, upside-down ones! The pads are covered in tiny bumps and a thin layer of slippery liquid. Together they make a grip that does not let go, even in a rainstorm, when the leaves are slippery.
More fun facts
- Tree frog toe pads are soft and covered with a pattern of tiny six-sided cells.
- Each cell is about 10 micrometers across, with channels about 1 micrometer wide between them.
- Glands open into the channels and keep the pads wet with watery mucus.
- Scientists once thought the wet mucus alone held the frogs on.
- Tests showed the frogs grip better because tiny peg-like bumps on the cells get very close to the surface.
- The channels let extra liquid drain away so the pads can press closer.
- This grip lets tree frogs cling to steep surfaces and even hang upside down.
Sources: National Institutes of Health
Questions kids ask
Is tree frog toe mucus just like water?
Almost. One sample tested was 1.65 times more viscous than water.