The warmer the weather, the faster the exchange. Other species may wait one second and then hold the flash for a full second. Some tropical species congregate in large numbers and flash in unison. Usually at dusk, male and female fireflies emerge from the grass. The flashes are usually male fireflies seeking mates.
Males outnumber the females fifty to one.
Females climb a blade of grass, flashing when males flash within 10 to 12 feet of the females. Exchanges of signals are repeated to 5 to 10 times until mating occurs. Sometimes females will devour males. The light emitted by fireflies is unique. The taillight contains two rare chemicals, luciferin and luciferase.