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Under optimal conditions, adult firebrats moult about every 9 days (English strain) or 13 days (American strain), irrespective of age, sex, or reproductive activity. The epidermis is activated on the 4th or 5th day of the 9-day stadium and the deposition of the cuticle follows 2 days later. There is a critical period for the secretion of a brain hormone on the 5th or 6th day of a 13-day stadium, equivalent to the 3rd or 4th day of the 9-day stadium; maximal activity in the ventral gland coincides with or follows shortly after this, also coinciding with the activation of the epidermis. Thus the control of moulting in Thermobia closely resembles that in the pterygotes.

Ovarian changes which accompany the changes in the rate of oviposition in founding females of Hodotermes mossambicus involve alterations in the number of ovarioles in which yolk deposition occurs, and in the proportion of oocytes which enter the final stage of maturation.

The female firebrat can mate from the first to the fifth day after ecdysis, but most mate between the first and third days. Mating initiates the deposition of proteinaceous yolk in the oocytes, oviposition following 2–4 days after mating. Thus, on the average, 4·69 days elapse between ecdysis and oviposition, with a standard error of 0·13 days, so that oviposition occurs almost exactly half-way through each adult stadium. The male also mates most actively during the first third of the stadium if exposed continuously to females, but the potential for full mating activity persists into the seventh day of the 9 day stadium in celibate males. The difference appears to depend on a finite capacity to produce spermatophores in any given stadium. As a result of these restricted mating periods, isolated pairs of firebrats can reproduce only if male and female moult within 3 or occasionally 4 days of each other.

Groups of Hodotermes mossambicus reproductives exhibit social behaviour. Maintenance of this behaviour by an individual depends on frequent contact of its body by the antennae of other termites. The antennae of the recipient do not play a role. Pairs on the other hand exhibit antisocial behaviour. Development of pair behaviour occurs when antenna to body contact is reduced or absent. Furthermore, at least the proximal parts of the antennae are required for full development of pair behaviour. Pheromones are not implicated in the change from group to pair behaviour.

Under optimal conditions, reproduction does not affect the rate of growth in female Lepisodes. In unmated male and female firebrats, an increase of weight after ecdysis is associated with a single phase of feeding activity, which terminates near the middle of the instar, coincident with the reconstruction of the midgut epithelium. In mated females, a greater increase in weight accompanies a more intense first phase of feeding, and at oviposition a short second phase of feeding commences. The weight of food consumed in this second phase is closely correlated with the weight of eggs laid, and evidently compensates for loss of reserves at oviposition.