Why do some seeds stick to your socks?

After a walk through tall grass, look down at your socks. Small brown bits are clinging there. Touch one with your finger. It feels prickly and scratchy.

Those prickly bits are seeds from plants. You shake your foot, and they still hold on. So why do some seeds stick to your socks?

Let's look very closely at one of these seeds. It is covered in tiny hooks. Each hook bends at the tip, like the letter J. The hooks are there to grab things.

Now look at your sock. It is made of soft threads with small loops. You brush past the plant, and snag! The hooks catch in those loops and hold on tight.

Animals brush past these plants too. A dog, a rabbit or a deer has thick, fluffy fur. The hooks catch in the fur the same way.

A plant cannot walk anywhere by itself. So its seeds grab on to things that move. A seed like this is a hitchhiker, which means a rider catching a free ride.

Off the dog trots across the meadow. The hitchhiker rides along, snug in the fur. What do you think happens to the seed next?

After a while, the seed drops off. The dog gives a shake, or the fur rubs against a bush. Plop! The seed lands on the ground, far from its mother plant.

Landing far away is good for the seed. Under the mother plant, the ground is crowded and shady. In a new spot, the seed has room and sunshine to grow.

Our special word is hitchhiker. Plants grow hitchhiker seeds with tiny hooks that grab socks and ride to new places.

Next time a seed hugs your sock, you will know a hitchhiker has found its ride.