Billions of insects are set to burst out of the ground in the United States this spring, in a rare event that hasn't happened in over 200 years.
If you're going to be in the US in late spring, you might just be in for a bit of a surprise as you may see a lot of periodical cicadas emerging from the ground.
The winged insects, which have red eyes and are completely harmless, usually emerge in 13- to 17-year cycles, but two of these groups are expected to emerge together for the first time since 1803.
This year, Brood XIII and Brood XIX are predicted to burst out of the ground together, meaning some states will see swarms of billions of the bugs, which make a loud clicking noise.
Wisconsin and Illinois are the ones that will mainly be affected, as billions of cicadas are set to emerge from the ground and are expected to cover signposts and pavements, as well as branches, and will also be seen filling the air as they fly.
Cicadas are among the insects with the longest life spans, living between 13 and 17 years if left undisturbed in their nymphal state, which is when they live underground for most of their existence, feeding on tree roots.
They build mud tubes, known as a cicada hut, when they are ready to emerge to the surface and shed their final skin on the surface of a tree, before coming into their winged adult form.
Given how long they can live underground the final stage of their life is staggeringly short, as they then die off within five or six weeks.
However, for those weeks it's going to be pretty intense in areas where cicadas are emerging, as there can be as many as 1.5 million of them per acre of land, meaning tens of billions of the insects could appear at the same time.
While their life above ground is extremely short-lived, the main reason the insects will come out is to mate, with the males making a loud clicking sound to attract females, with the noise levels being similar to a lawn mower or a passing jet plane.
Tree branches are then often weighed down by the amount of eggs the adult cicadas lay, and they can cause further damage to the environment as the feed on young trees and vines.
The University of Illinois explained: "When the cicadas start dying and dropping from the trees later in the spring, there are large numbers on the ground, and the odor from their rotting bodies is noticeable
"In 1990, there were reports from people in Chicago having to use snow shovels to clear their sidewalks of the dead cicadas."
Brood XIX's offspring will then next emerge from the ground in 2037 after 13 years, while Brood XIII has a 17-year life cycle meaning they will next be seen in 2041.
