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Common Eastern Firefly

Photinus pyralis

HarmlessUncommon

Quick answer

Harmless beetle that lights up at dusk. Safety level: Harmless.

How to identify the Common Eastern Firefly

A soft-bodied beetle with dark wing cases edged in yellow.
The shield behind the head is yellow and pink with a black spot.
The end of the abdomen glows yellow-green in the evening; males flash in a "J" shaped swoop.
Size: 10–14 mm.

Where it lives

Common in eastern North America in lawns, meadows, field edges and woodlands, especially near water, from late spring to midsummer.

Is it dangerous?

Fireflies are harmless to people. They do not bite or sting. They contain bitter chemicals that make them distasteful, so pets and reptiles should not eat them.

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Children and pets

Safe to watch; release after catching.

What to do

Turn off garden lights to help them find mates.
Avoid pesticides on lawns.

Fun fact

Each firefly species flashes its own light pattern.

Frequently asked questions

How do fireflies light up?

A chemical reaction in their abdomen produces cold light, which they use to find mates.

Why are there fewer fireflies?

Light pollution, loss of habitat and pesticides all reduce firefly numbers.

Are fireflies poisonous to pets?

They contain chemicals that can harm small pets and reptiles if eaten, so keep them away.