Firebrat

The reproduction of the Firebrat or silverfish is preceded by a ritual involving three phases, which may last over half an hour. In the first phase, the male and female stand face to face, their trembling antennae touching, then repeatedly back off and return to this position. In the second phase the male runs away and the female chases him. In the third phase the male and female stand side by side and head-to-tail, with the male vibrating his tail against the female. Finally the male lays a spermatophore, a sperm capsule covered in gossamer, which the female takes into her body via her ovipositor to fertilise the eggs.

The female lays groups of less than fifty eggs at once, deposited in small crevices. The eggs are oval-shaped, whitish, about 0.8 millimetres (0.031 in) long, and take between two weeks and two months to hatch. Silverfish usually lay fewer than one hundred eggs in their lifetime.

When the nymphs hatch, they are whitish in colour, and look like smaller adults. As they moult, young silverfish develop a greyish appearance and a metallic shine, eventually becoming adults after three months to three years. They may go through seventeen to sixty-six moults in their lifetime, sometimes thirty in a single year, which is much more than usual for an insect. Silverfish are one of the rare species of insect that continue to moult after mating.

The lifespan of a silverfish varies from two to eight years.