Fireflies lay eggs in the soil in late spring or early summer. The eggs hatch into larvae called glowworms after 3-4 weeks. The glowworms feed and grow throughout the summer, then burrow underground to hibernate in winter. In spring, the glowworms emerge and pupate for 1-2 weeks before emerging as adult fireflies. The adult fireflies emerge at night in early summer to find mates and reproduce through bioluminescent signals, completing their lifecycle.