There are certain things for which Oklahoma summers are known: Oppressive heat, suffocating humidity, devastating drought, continually running air conditioners and the song of cicadas.

To be sure, no Oklahoman is surprised by these well-known summertime characteristics – these are as certain as tornadoes in the spring, football in the fall and ice storms in the winter.

Some summers are worse than others – 2023 was one of the hottest – and electric bills aren’t getting any cheaper as we cool our homes and offices as best we can. And every year there’s the unmistakable and incessant screeching of the cicadas.

Just as sure as there are ticks hoping to find a new home on our bodies and Oklahoma lawns turn a crunchy brown, cicadas are going to emerge from the millions of eggs that are laid each year.

While there are both annual and periodical cicadas – annual cicadas emerge every year, while periodical cicadas come around every 13 or 17 years, depending on the brood – there’s never a shortage of the racket-producing critters. While the life cycle of periodical cicadas makes it sound like we ought to have a dozen to 16 years of summer solitude, unfortunately all the female cicadas didn’t get together at one time eons ago and lay all their eggs so that we’d be able to anticipate the noisy years followed by silent years. It’s a continuous cycle of broods emerging with one singular goal: Mating and laying millions more eggs.

But in 2024, for the first time in more than 220 years, two separate broods – the 13-year and the 17year – will simultaneously emerge in the same year. It’s the first time this has happened since Thomas Jefferson was president, Oklahoma was part of the expansive Louisiana Purchase and Napoleon was attempting to conquer Europe. And if you were to miss this rare occurrence – not much chance of that – the same dual emergence won’t happen again until 2245.

So with two separate broods of periodical cicadas emerging, along with the annual cicadas already expected, there will be even more cicadas in the trees and bushes of Oklahoma and two dozen other southeastern and midwestern states.

While the millions upon millions of cicadas expected this year is mind-boggling – some, channeling their best Carl Sagan impersonation, have even predicted “billions and billions” – the 13-year and 17-year broods are the loudest of them all, partially due to the sheer number of cicadas emerging at once.

— When will they emerge?

Cicadas emerge beginning about mid-May, and continue through late June – when trees have grown leaves, and about the same time Iris flowers bloom. According to Cicada Mania, a website dedicated to cicadas (in case the name didn’t give it away), the Oklahoma insects begin to emerge when the soil eight inches underground reaches 64 degrees, and are frequently triggered by a warm rain. They emerge at night, shed their skins (or exoskeleton) and spend the next five weeks doing what they do best – mating, laying millions of eggs and then dying.

When all those eggs hatch, the nymphs fall from the trees onto the ground and then burrow deep into the soil. Once underground, they feed on tree sap from tree roots. In 13 or 17 years, the cycle repeats itself.

The cicada exoskeleton (or shell), familiar to all Oklahomans, are abandoned as they transform from wingless nymphs into adults, leaving behind brown husks that can be found on trees or practically anything onto which the little buggers can climb for the transformation.

Because of their years spent underground, periodical cicadas have the longest life cycle of any known insect, according to the OSU Extension Office.

— What are cicadas?

There are more than 3,000 species of cicadas in the world, and Oklahoma is home to more than a dozen varieties of annual cicadas, according to Cicada Mania, which calls them “the most amazing insects in the world.” Some of those Sooner species are southern grass cicada, swamp (or morning) cicada, northern dusk singing cicada, lyric cicada and two varieties of the dog-day cicada.

What cicadas aren’t are locusts, which are from the same family, but are often mistakenly referenced as interchangeable. Cicadas are also sometimes called jar flies, possibly because when you catch one and hold it in your hand, it “jars” or vibrates, but it may be derived from their constant “singing” that might “jar” or unsettle some people’s nerves who are not accustomed to hearing them for hours on end.

Adult cicadas are about 1½ inches long, with a wingspan twice that length. Their bodies are often dark (ranging from blackish to brownish to greenish), with dark red-brown eyes and veined wings.

However, their most noticeable feature is their loud “courting” sounds.

— Why are they so noisy?

It has been said that for its size, the cicada can make as much noise as a large animal, enough so that it can be heard for up to a quarter mile away. Wherever you go during the peak of summer you can hear cicadas – remember, there are millions of them.

Only the males sing, vibrating their whole body. They use drum-like structures on their abdomen, called cymbals, to create a loud, high-pitched buzz to attract female companions, who respond with a quick flick of their wings together. This mating call and response, which sounds to some like the whining of electrical wires rising and falling, is a shrill noise to some, and a drowsy “song of summer” to others.

The males’ synchronized calls produce congregational songs which not only attract females, but establish territory. The sound – which has been called singing or serenading or screaming or screeching, depending on your tolerance level – can reach an astounding 90 A-weighted decibels, which is as loud as a lawnmower, motorcycle, tractor or a jetliner landing.

While cicadas seem to be a constant soundtrack for Oklahoma summers, as dusk turns to night, many cicadas really find their voice. Not only do they tend to sing at night, but also during particularly hot weather, and as a pack to escape predators.

It has been observed that when a cicada “group” suddenly seems to fall silent at the same time when you disturb their surroundings, what is perceived as a “group” is usually a single cicada. Their sound is so loud that it’s common to mistake them as multiple cicadas. They’re rather skittish, and will stop singing the moment they see a possible threat. Their synchronized chorus doesn’t start or stop simultaneously. Usually one begins the song, and others nearby join in. Likewise, they stop one by one before starting up again.

The sheer number of cicadas “singing” could be ear-shattering, but they are otherwise harmless to humans and pets.

— Are cicadas dangerous?

Cicadas are not dangerous or harmful to humans, pets, household gardens or crops. They do not bite or sting. They are neither poisonous nor venomous. If your dog or cat eats a cicada, it’s okay if it’s a small amount. Eating larger quantities of cicadas can cause an upset stomach or vomiting.

Humans can also eat cicadas (they’re similar to crickets). But if you’ve got seafood allergies, cicadas shouldn’t be on your menu.

Despite their overwhelming numbers, they can actually provide a few environmental benefits, including being a valuable food source for birds and other predators, such as cats, dogs, foxes, raccoons and other insects.

— Cicadas in folklore

There’s a long-repeated folk legend – usually in northern states – that says when you hear the first song of the dog-day cicadas, it means there’s just six weeks until the first frost. Well, this may not be a precise predictor of frost and the coming of winter, but there is some merit to the claim. (When I lived in Ohio, I marked the calendar upon first hearing a cicada, and, sure enough, our first frost was six weeks later.)

That frosty-weather folklore doesn’t hold true in Oklahoma and throughout the Southeast, which is why the southern version usually heralds warm, dry days ahead. Which is why during the dog days of summer, when the heat and humidity are unbearable, the cicadas’ song can be heard over the air conditioner in front of which you may be sitting.