I appreciate how absolutely done with all of this koMarisa looks.
It's mainly because of their weak body structure and food competition caused by uncontrolled births.It's is said that koyukkuris without their parents' protection only have a survival rate that is below several percent.Koyukkuris without their parents' maintenance have a high chance of dying of bacteria and fungi infections, such as the yukkuri mold. A newly born Yukkuri's pastes cycling ability which provides immunity is weak, so they formed a habit of stimulating cycling by stretching their bodies and letting their parents massage them to assist immunity.