Lightning bugs often light up backyards in the summer. Why you may see more fireflies.

It's a right of passage in Iowa: Stepping out into your backyard to see fireflies lighting up the night sky.

There are more than 170 species of glowing insects known as Lampyridae in North America. Across the globe, there are more 2,000 kinds of lightning bugs that have been around for millions of years, according to USA TODAY.

What are the top threats to firefly's habitat?

Increased artificial light such as street lights are threatening firefly populations by interfering with the insects' mating rituals. Droughts threaten their habitats along with agricultural pesticides that harm the larval stages. Fireflies are also losing their habitats to development, according to USA TODAY.

Firefly vs. lightning bug: What's the difference?

No matter what you call them, fireflies and lighting bugs are the same thing, Iowa State University Extension entomologist Donald Lewis wrote in 2007. The names are used interchangeably to describe insects from the Lampyridae family.

How do fireflies glow?

The light from fireflies comes from a chemical reaction known as bioluminescence. When oxygen meets with a chemical known as luciferin and luciferase, it generates light. The flash creates a "cold" light that produces the light with little heat, according to the Iowa Department of Natural Resources.

When do fireflies come out?

Fireflies thrive in moist, humid environments. In years when warm, summer weather comes earlier, so do fireflies, according to the Farmer's Almanac.

Iowa has seen drought-busting rain over May and June and temperatures in the 90s over the last few weeks. February was also the warmest-ever in Des Moines. This mild winter could mean larger lightning bug populations in your back, according to the Farmers' Almanac.

What do fireflies eat?

Fireflies are beneficial to gardens. They feast on slugs and snails which can harm plants such as beans, lettuce and tomatoes, according to Better Homes and Gardens. Fireflies also don't carry diseases like other backyard insects.

Kate Kealey is a general assignment reporter for the Register. Reach her at [email protected] or follow her on Twitter at @Kkealey17.

This article originally appeared on Des Moines Register: Why do lightning bugs glow? More rain means more fireflies