1. Mosquito

A dozen biting, stinging, venom-injecting, shock-inducing, and disease-carrying insects and arachnids. These are some bad bugs.

The deadliest insect is, in fact, the deadliest critter in the entire animal kingdom. It is the humble mosquito, which kills more than 700,000 people every year. Skeeters are vectors for a host of nasty diseases, including malaria, dengue, West Nile, yellow fever, Zika, chikungunya, and lymphatic filariasis. Malaria is the big one: In 2017, roughly 435,000 people died of the disease worldwide. That’s one person every 30 seconds. Mosquitoes have a special organ, the maxillary palp, which detects CO2 released from our breath and guides them to us, where they consume three times their own weight in blood. Mosquitoes are known to prefer beer drinkers, probably because drinking a beer increases the ethanol content in your sweat. Ethanol turns mosquitoes on. Plus, all booze increases your body temperature, which makes you easier for a mosquito to find. People of greater body mass attract more bugs for the same reason. Mosquitoes also prefer people with O type blood. Nobody knows exactly why, but the assumption is that O-blood-type people smell better, to mosquitoes at least, than everybody else.