Experts say there are more eastern U.S. fireflies than usual this year because the region has had rainier springs and warmer summers during the past couple of years. Young fireflies, called larvae, live underground or in piles of leaves and do especially well when the ground is warm and soggy.

That doesn’t mean fireflies are doing well overall. The insects have suffered due to habitat loss and the use of pesticides. Light pollution—bright light from buildings, such as in cities—can also be harmful to fireflies because it makes it harder to see them. If fireflies cannot see each other glowing, they can’t find mates. Experts say these factors have caused there to be fewer fireflies in many places.

But you can help! Here are a few ways you can support the health of firefly populations.

• Turn off outdoor lights when they are not needed. Close the curtains to keep indoor light from glowing outside.
• Plant native vegetation (plants that naturally grow in your area).
• Keep fallen leaves in your yard. Don’t throw them away.
• Use fewer outdoor chemicals, such as pesticides.
• Leave fireflies alone. Enjoy their glow, but don’t capture them.