Monogenea are usually hermaphrodites. This means that they have both sexes. First they are males, and only later do they become females as well. They have direct life-cycles with no asexual reproduction (unlike the Digenea). In those types of Monogenea that lay eggs, the young ones grow to a larval stage called an "oncomiracidium". It is at the "larva" stage that they are able to travel from one host creature to another. When they are adults, Monogenea eat the blood, mucus, and epithelial cells of their host creature.