To make babies
they need to make babies for population growth
but some ppl also have sex for fun,pleasure
lol hope it helps
<span>Diffusion and osmosis
Diffusion occurs because of the movement of molecules from the region of higher concentration to the region of lower concentration. This movement of molecules occurs due to a thermal motion. Diffusion normally occurs between two compartments having difference in concentration. In case of fluid it moves from the region of higher concentration to the region of concentration until a balance is reached. The process of diffusion is very important for the humans as well. The oxygen that humans breathe in gets diffused with the blood.
Osmosis is the passive movement of water. <span /></span>
Sorry for the handwriting
I believe your answer should be glacial drift
