In fact, they're beetles:
lampyrid beetles to be exact.
Many lampyrid larvae and adults glow when they are disturbed, which is thought to serve as an aposematic signal (Sivinski 1981; Underwood et al.
To date no lampyrid pheromones have been isolated or characterized (Lewis 2009) except for some species of the Asian firefly genus Pyrocoelia (Shibue et al.
Terrestrial crabs, carabid, drilid and
lampyrid beetles, and snail eating birds, such as coucals, francolins and guineafowl, are potential predators, as are the larger lizards (e.g., Varanus spp.) and a number of omnivorous mammals such as baboons, mongooses, genets, civets, otters, honey badgers, jackals and some rodents, as well as insectivores such as shrews and hedgehogs.
They are popularly known as fireflies, but these dipteran flies are unrelated to true fireflies (Lampyris noctiluca and other
lampyrid beetles), which are in fact beetles.
Lightning bugs (
Lampyrids) and Soldier Beetles (Cantharidae) are excellent predators of soil bodied insects like aphids.
carolinus and 13 additional East Tennessee
lampyrids. Photinus carolinus is protandrous, with the first males appearing on May 24 on average, approximately half-peak male abundances reached by Jun 5, first females by Jun 9, with the final night of peak male activity being Jun 11 (Faust & Weston, 2009).