Some months later, the colony's scientists come to a disturbing realization: the grendels and the aquatic samlon are the same species. Their life cycle is similar to that of terrestrial frogs – the herbivorous samlon are in fact the juvenile form of the carnivorous grendels. The juvenile samlon are male, and become female when they mature. Interaction is unnecessary, as the grendels continually lay unfertilized eggs in the water for the samlon to fertilize. Like some species of frogs, the grendels are cannibalistic – if no other prey is present, they will eat their own young. On the colony's island, all other prey sources were previously exhausted, and the grendels have turned to cannibalism as the rule rather than the exception. The colonists have exterminated the adult grendels. But as there is now no check at all on the samlon population, they all become grendels, meaning that instead of a few dozen grendels, there are now thousands.