You know those little green things that stick to your clothes?

Question

They stick to you if you roll in the grass or climb a tree or anything involving plants and they're sort of semi-circle shaped, yeah what are they? why is it that you can't see them when they're on the actual plant? what is their purpose? Iknow, very dumb question, but i've always been curious. :)

Answer 1

Seeds.  This is the method plants spread their seeds.  They also stick to the fur coats of animals that brush against them.

Answer 2

Burs?

Answer 3

They are called beg a lice.They are just seeds and its natures way of getting them around to make more plants.