Bloodthirsty Mosquitoes

As a scientist studying mosquitoes, you accidentally unleash a swarm of genetically-modified mosquitoes that have an insatiable thirst for blood. The only way to stop them is to perform surgery on their ventral nerve cords to cut off their feeding signal. But as their thirst for blood becomes uncontrollable, the mosquitoes begin to mutate and grow to massive sizes, becoming a horrifying threat to humanity.