Don’t Freak Out—It’s Just Spiders Raining from the Sky

A spider species named Parawixia bistriata has one of the most terrifying habits imaginable. Think of your worst nightmare, double it — and you still might not guess what this eight-legged arachnid gets up to in summertime in Brazil. You see that dark mass of thick raindrops falling from the sky? Yeah, that’s not rain…it’s actually hundreds of spiders raining down all around you. Nature can be even scarier than horror movies!

It’s Raining Cats and Dogs — and Spiders

People call spiders creepy crawlies, but that doesn’t mean they only crawl on the ground. Have you ever seen them hanging out in dark corners on the top of your ceiling or high on a fence or tree in your backyard? Well, the spiders in Brazil behave similarly, but there are hundreds of them at once.

Residents in São Thomé das Letras, in the state of Minas Gerais in Brazil, captured this real-life nightmare in photos and videos shared by the Daily Mail. The images depict what looks like the apocalypse: massive, black spiders seemingly falling straight from the clouds above. The people who filmed this must have been extremely brave; just watching it gives me a phantom crawling sensation on the back of my neck.

NDTV World shared a video posted on X, with the videographer @Gennady Simanovsky explaining: “Spiders have taken over the sky in Brazil. This apocalypse happens every year from December to March in hot and humid weather in rural areas. Huge groups of up to 500 spiders weave webs that stretch across the entire sky. There is no danger to humans.”

Expert Opinions

Even though one might think spiders raining from the sky is a bad omen or a sign of something seriously wrong, this behavior is actually quite natural.

Biologist Kayron Passos told a local outlet, per the Daily Mail, that this occurrence is an elaborate mating ritual. “It’s a spider orgy,” he says. “The females have something called a spermatheca, where they store the semen of different males to fertilize the eggs. This way, the female ensures that she will have several different offspring and increase genetic variability.”

To be fair, the explanation behind this behavior doesn’t exactly ease the creepiness factor. Another expert, arachnologist Dr. Ana Lucia Tourinho, who has a PhD in biological sciences, says that this is an example of a spider species that is more social than usual.

“The strategy of staying together in a group increases the food supply for the offspring and juveniles,” Dr. Tourinho says, per Daily Mail. “The colony usually forms every year, and most of its members are related, typically generations of mothers and daughters living together. After mating, however, they disperse.”

A Common Occurrence

This isn’t the first time videos of spiders falling from the sky in Brazil have gone viral. In 2019, the Guardian shared several videos of a similar occurrence, including one taken by João Pedro Martinelli Fonseca when he was traveling to his grandparents’ farm in Espírito Santo do Dourado in Minas Gerais. He told one local paper that he was stunned and scared (as anyone would be!). His grandmother, Jercina Martinelli, was used to it, though.

“There were many more webs and spiders than you can see in the video,” she says. “We’ve seen this before, always at dusk on days when it’s been really hot.”

At the time, Adalberto dos Santos, a biology professor specializing in arachnology at the Federal University of Minas Gerais, explained the phenomenon. He told the Guardian that the web that holds these spiders up is so invisible to the human eye that it looks like the spiders are falling, but they are actually sliding down their webs. That’s not much comfort if you are in their path, though!

In 2015, spiders rained from the sky in southern Australia, according to National Geographic. The spiders are tiny adult sheet-web weavers or money spiders, Robb Bennett, a research associate in entomology at the Royal British Columbia Museum in Victoria, told a local news outlet, per National Geographic. They crawl to a tall fence pole or a plant, then shoot a web into the sky to be raised in the air like Spider-Man. The web then falls to the ground, making it look like it’s covered in snow.

“It’s a reverse-parachute effect—they’re going from the ground into the air,” Bennett says. “It’s awe-inspiring.”

Flying Spiders

Spiders can’t fly, despite popular belief, but they can use their webs to glide or balloon through the air, reaching heights of up to two-and-a-half miles. Others, like the wall crab spider, simply use their unique body design to glide through the air. Spiders may take to the air for many reasons, such as mating (like those in Brazil) or escaping their current habitat. They may also be looking for insects to eat. No matter the reason, it’s pretty impressive that these spiders are so mobile, even if it is a little terrifying at the same time.