I hate mosquitos!

Fuck, I went to buy mosquito coils, and now I see in the Internet several articles saying that these things contain carcirogens! Depending exactly what chemical you're analyzing, these things may be up to 137 times as poisonous as a regular cigarette!

Exactly what is the raison d'etre of the mosquitos? What's their evolutionary role in our world? They should be extinguished, and the same goes for cockroaches!