Spiders often get filed under 'creepy,' but they're helpful, too

Are spiders a scary omen of doom, or just a great helper? It might just depend on whether you're a human who hates mosquitos, or the mosquito itself.

In 2017, scientists found that all of the spiders in the world consume between 440 and 800 million tons of insects and other pests every year.

Wait... "other pests?"

Yes. In addition to insects, some larger species may eat animals including frogs, lizards, snakes, fish, birds and bats.

Earlier this year, USA Today reported that orb weaver spiders also have another interesting skill: Trapping a firefly and using its glowing bulb to attract even more insects. The study was published in Current Biology and based on the behavior of the spider species in China, Japan and Korea.

Others are reading: How a 'zombie firefly' lures other bugs to their death

"As far as I know, this is absolutely unheard-of in other spiders," Linda Rayor, professor of spider biology at Cornell University and president of the American Arachnological Society, told USA Today in August.

Are spiders dangerous? Which species are the most harmful to humans?

According to the Indiana Department of National Resources, Indiana has about 400 known species of spiders, but only two can seriously injure humans: The Black Widow and the Brown Recluse. If bitten by either, it's suggested to seek medical attention immediately.

How to identify a black widow

According to a guide from Purdue University's entomology department, a female black widow is black and about the size of a penny with its legs extended. On the underside, the female only is marked with a red or yellow hourglass shape.

Its poison affects the nervous system, Purdue's resource says, and can cause the following symptoms: dizziness, blurred vision, difficulty breathing, nausea and severe pain at the wound site.

How to identify a brown recluse

Purdue's guide says a mature brown recluse spider's leg span is about the size of a half dollar. Its color ranges from light tan to deep reddish brown, and it has a darker contrast fiddle-shaped area on its back.

According to Purdue entomologists, it's especially dangerous to children, the elderly and those with health concerns, but fatalities are rare. Reactions include: extreme pain, a small white blister at the wound site, inflammation and a sore. It can take several weeks to recover.

USA TODAY reporters Claire Thornton and Doyle Rice contributed.

This article originally appeared on Indianapolis Star: Spiders often on display for 'spooky season,' but most aren't harmful