Have you ever ask yourself why you eat animals and plants? We all know human being survive by eating what was planted and some animals, we take water also, but if we don't eat and drink water, what would happen to human being? He will probably died, let me say he will died or have you seen anybody that didn't eat for a month and survived.

This also goes to mosquitoes, mosquitoes suck human blood to survive, simply because human it their host. they depends on human being blood. That's what they feed on and Mosquitoes normally died after seven days whether they suck blood or not and they didn't give birth.