Are you extra delicious to mosquitoes?

The word “mosquito” means “little fly” in Spanish, but there’s nothing small about their bloodsucking reputation, especially as the brain-shrinking Zika virus gains momentum. And, it turns out mosquitoes prefer some people over others, according to a recent “taste test” involving mosquitoes and human twins.

Before you run away from the next mosquito, did you know that not all of them prefer to munch on humans? See, there are about 3,500 different species in the world, and they enjoy a wide range of food including nectar, reptiles, birds, and different types of mammals besides us. There’s a mosquito species in particular called Aedes vexans, and these are the suckers that feast on humans. Sadly, they can be found in every state, which is probably why it seems like all mosquitoes are out to get your blood.

Speaking of blood, mosquitoes may discriminate one type from another. An old experiment found that these tiny bugs preferred “Type O” blood, or red blood cells that do not have proteins on their surface, but later studies claim to have debunked this myth. Mosquitoes usually focus on body temperature, body odor, and carbon dioxide exhaled in your breath, rather than blood type.

Recently, scientists gave mosquitoes the option of traveling down one of two tubes, where a different person waited at the end of each. When the mosquitoes had the choice of feasting on the blood of identical human twins, they showed no preference between the two for their meals. However, when they were able to choose between two fraternal (non-identical) twins, the mosquitoes did pick different snacks. Why? Well, identical twins have the same genes, which are biological blueprints passed down from parents that tell our bodies how to grow. Fraternal twins might share the same birthday, but their genes are much more different than identical twins. So, scientists believe mosquitoes could tell when the blood was basically the same or different.

If you’re already reaching for the nearest bug spray, here’s some good news. Scientists are creating mutant mosquito swarms to lower their disease-spreading populations! See, warmer than usual temperatures have pressured tropical mosquitoes to seek cooler climates in places like the Florida Keys, a group of islands southeast of Florida. They’ve brought exotic diseases with them, including chikungunya and dengue, which can cause skin rashes, muscle pains, and fevers. Since mosquitoes can spread viruses when they suck our blood, health officials are concerned. The little vampires have also spread foreign illnesses like yellow fever, West Nile Virus, and malaria in America.

Unfortunately, the tough buggers have been resisting all kinds of manmade poisons called insecticides, so scientists have now created mutant swarms with adjusted DNA. Basically, DNA has blueprints that tell our cells how to grow, and the mutant mosquitoes will cripple future generations by making them unable to create babies. Some citizens are protesting, though, because they’re afraid of bloodsucking mutants invading their neighborhoods!