Who can walk on a wall?

Put your hand flat on a wall. Feel how smooth and flat it is. There is nothing there for your fingers to grab.

Your feet need the floor under them. If you stepped onto a wall, you would slip right off. So who can walk on a wall?

Meet the gecko, a small lizard with wide, soft toes. A gecko can run straight up a wall. It can even walk across the ceiling!

Why doesn't it fall? Let's look under its feet. Each toe has a toe pad, which means the soft, flat cushion under the toe.

Every toe pad is covered in tiny hairs. They are much too small for your eyes to see. There are so many that nobody could count them all.

The gecko presses its foot down on the wall. Then all those little hairs touch the wall at once. What do you think those hairs do next?

Each little hair holds on to the wall, just a tiny bit. All together, they hold on strongly. Their pull is stronger than the pull down, so the gecko stays put.

To take a step, the gecko curls its toe up from the tip. The hairs let go, and the toe pad peels off the wall. Then the gecko presses its next foot down, higher up.

Flies and spiders have little hairs on their feet too. That is how they walk on walls as well, just like the gecko.

Two words to remember: gecko and toe pads. A gecko walks up walls because tiny hairs on its toe pads hold on.

Sleep well, little one, and dream of climbing high and holding on tight.