While Rayun (pronounced rah-yoon) eggs are most commonly found in cold habitats, they weren't initially discovered there. Soon after Rayun were identified, they were forced to migrate to colder environments due to excessive predator populations in their original habitat, the grasslands.
Rayun eggs are very sensitive to cold temperatures, and the Rayun population quickly started to decline when colder months came around. In an attempt to keep the population stable, the Science and Research Center started an expedition to gather Rayun eggs during colder temperatures and release them back into the wild when it became warm enough. This caused the Rayun mothers to become very hostile towards Ark citizens, so eventually the egg collections were ruled illegal. Instead, a tradition started in order to keep the Rayun from becoming extinct where Ark citizens would craft small blankets and leave them near Rayun nests in hopes that the mother would find and use them to keep their eggs and young children warm.
While Rayun may often act hostile, they generally are not dangerous at all. They are a very proud species and value independence, and are thus nearly impossible to keep in captivity. Despite this, young Rayun are known to be relatively friendly towards Ark citizens, and will usually accept food and other gifts when offered.