The Pyralis firefly is a common firefly in North America. This partly nocturnal, luminescent beetle is the most common firefly in the USA.
At night, the very end (the last abdominal segment) of the firefly glows a bright yellow-green color. The firefly can control this glowing effect. The brightness of a single firefly is 1/40 of a candle. Fireflies use their glow to attract other fireflies. Males flash about every five seconds; females flash about every two seconds.
The firefly is about 0.75 inch (2 cm) long. It is mostly black, with two red spots on the head cover. The wing covers and head covers are lined in yellow. Like all insects, it has a hard exoskeleton, six jointed legs, two antennae, compound eyes, and a body divided into three parts (the head, thorax, and abdomen).
Both the adults and the larvae are carnivores (meat-eaters). They eat other insects (including other fireflies), insect larvae, and snails.