(WTAJ) — The current brood of cicadas, Brood X, are here, back from underground, and millions are taking over wherever they want. There are annual cicadas, which we can see every year, and there are periodical cicadas, which live underground for 13 or 17 years and mass emerge in broods, like Brood X.

Cicadas are harmless and can’t bite or sting. Check out some more facts about cicadas that might surprise you.

• Cicadidae can be found on every continent except Antarctica. They thrive in warm environments like the tropics, which makes paces like Australia, Latin America, and the Western Pacific hotspots for cicadas.
• Cicadas can’t eat or bite because they lack jaws. They use a straw-like appendage to suck nutritious fluids from trees and their roots to help them survive underground.
• Cicadas drink a lot and pee a lot of fluids. Some people experience what might seem like spit, but it’s actually “cicada rain,” that many have dubbed “honeydew.”
• Cicadas likely have an internal clock calibrated by mysterious environmental cues, keeping their circadian rhythms accurate and tracking the years until they’re ready to emerge and mate.
• Swarming cicadas are loud, producing mating calls that range between 80 and 100 decibels on average. This rivals a construction excavator at 80 decibels, church bells at around 70 decibels, and even a classic motorcycle at about 88 decibels.

Cicadas’ wings are water and bacteria-proof. According to research published in 2013, the cicada’s wings kill bacteria on contact with a layer of incredibly tiny spikes and a chemical coating. The special defense doesn’t work on all bacteria, just those whose cell walls are soft enough to slump between the spikes. The same mechanism also keeps them dry. These super-small structures are hard to replicate, but last year a team of researchers managed to make copies of the cicada wing’s complex surface!

The cicada’s strange life cycle may have evolved to avoid predators. Scientists still aren’t sure exactly why two certain species of cicadas only come to the surface and mate once every 13 or 17 years. They speculate that the prime number life cycle may have developed over millions of years to avoid synching up with booming populations of predators, which tend to rise and fall on two- to 10-year cycles, wrote Patrick Di Justo for the New Yorker in 2013.

Cicadas have many natural enemies, including birds and rodents. Another example is the Cicada Killer, a wasp that grows up to two inches long. Females hunt cicadas after mating, grappling in mid-air and injecting paralytic venom through the cicada’s hard exoskeleton. Back in her burrow, the wasp lays an egg on the cicada and seals it shut in a chamber. In a few days, the egg hatches and eats the cicada alive.

The cicada’s predators include humans, who eat cicadas more often than you may think. Their flavor varies from person to person, but most describe a green, earthy flavor comparable to asparagus. Many say they also taste like shrimp. One chef in Leesburg, Virginia has added Cicada Tacos to his menu while they’re “in season.”

Several species of the parasitic fungi Ophiocordyceps specialize in invading the bodies of cicadas, infecting them while underground. They become possessed by the mushroom, digging back up to the surface before dying in a fungal explosion.

Another fungus can drive zombie cicadas “sex crazy,” so they lose their genitals and abdomens. The dormant Massospora cicadina fungus resurfaces alongside periodical cicadas, and only infects the males. It causes the bug’s abdomen and genitalia to fall off, leaving a mass of fungal matter. This drives them to reproduce, but not to mate. Instead, the male imitates the sounds of a female in order to attract other males. The sole purpose is to spread the fungus to more males in the brood. Scientists believe roughly 5% of cicadas go through this.