Buzz, prick, itch and annoy!

I'm gonna do a Simon C. and do a bit of a rant.

Question: WHY DO MOSQUITOS EXIST?

They are of no use to anyone/thing/other. A cow can be useful for eating, milking or riding. The grass a cow eats is useful for feeding cows, or goats, or vegetarians.

But how is a mosquito useful? What do they achieve by biting you and making you itch? Sure, they take your blood to reproduce. But for what? To bite us again, that's what!

And yes, I did get bitten by a mosquito.