(Northern US, Western US, Florida) Any beetle of the family Lampyridae, which exhibit bioluminescence during twilight.
2000, Exploring Life Science, 2: Bats—Cave Life, Marshall Cavendish, page 96,
Fireflies are the best-known insects that produce light. […] Many fireflies use their light to communicate, particularly at mating time when males and females have to get together.
Mac + Safari
iPhone + iPad
Google Chrome
Mozilla Firefox
Opera
Microsoft Edge