This suggestion is pretty cut and dry and like a year old, but oh well Like Rogue Males, there could be Lonely Ladies who carry similar genes as Rogue Males, mate with your male nichelings, and steal nests like dodomingos in order to have those babies, which will then either become Lonely Ladies or Rogue Males depending on their gender, though they will follow her around in the tile behind her like a bearyena and her cub until they're old enough to wander away. Rogue Males and Lonely Ladies