[7] The common name, big dipper firefly, is due to the characteristic flight of the males, whose trajectory appears to follow a J-shape, lighting on the upswing.

[3][8] During flight, this J-pattern is used alongside light flashing to attract females, who rest on vegetation and signal back to males if interested.

They have flat black or brown bodies with wing coverings, or elytra, that extend the length of their entire thorax and abdomen.

[12] Some natural habitats of these fireflies include meadows, fields, wetlands, desert canyons, and dense forests, and while they can successfully thrive in all of these areas, they require moisture to survive at all life stages.

[4] Population studies have been done to investigate whether P. pyralis has always been endemic to the northeast regions of North America, especially because the species continues to occupy a wide variety of habitats across the continent.

It has been discovered that ancestrally, the North American population originated in Texas during the Miocene epoch before migrating to the central states of the US and more recently, the Northeast coast.

The biggest threats to their populations include light pollution, pesticide use, climate change, and human building and development in their habitats.

[14] Photinus pyralis contain steroid compounds called lucibufagins, which make them taste bad to potential predators, such as birds, bats, and other insects.

[16] Excretion of unpleasant fluids containing lucibufagins from the areas along the elytra and pronotum is the result of tactile stimulation and has been referred to as reflexive bleeding.

These nuptial gifts, also known as spermatophores, are a combination of sperm and high levels of protein, hormones, defensive compounds, and other nutrients which the females will subsequently use to feed the eggs should she choose to mate with the male.

Although it ends up being a high cost to males, those with larger spermatophores tend to see increased reproductive success because they are able to provide females with more nutrients to sustain future offspring.

[29] Luciferase requires oxygen, luciferin and adenosine triphosphate (ATP) to catalyze a chemical reaction that produces bioluminescence in these insects.

[30] It has been shown that the glow is not controlled by the tracheal end cells (which were thought to contain valves) nor by central nerve impulses through studies involving low oxygen conditions.

Because it is known that luciferase is activated by oxygen, luciferin, and ATP, the assays were specifically pertaining to reduction-oxidation reactions that occurred in various organisms.

Recent studies have shown that the luciferase protein has been found specifically in peroxisomes of many eukaryotes, the organelles[33] responsible for carrying out oxidative reactions and producing hydrogen peroxide as a byproduct that is quickly removed.