He told Tuvok that they had been left to die on the moon and were afraid that a creature known as a morrok would kill them. When a Drayan search party landed on the planet, Tuvok helped the children evade the Drayans. The next day Corin and one of the other children were gone, and Tuvok only found their clothes.
When the Drayans found Tuvok, they explained that the children were not children but adults. The Drayan life cycle is reversed and that the children had come to the moon which was a sacred shrine of the Drayans to die of natural causes. (VOY: "Innocence")