Silky the hamster is hairless due to a genetic mutation, according to the Oregon Humane Society in Portland.
In a news release, OHS staffer Diana Gabaldon said that because Silky, "isn't fluffy like a normal hamster," she gets cold easily.
Silky "does need to be kept in a heated environment, especially during the winter, and have a higher protein diet to keep her warm," Gabaldon said.
But recently, on a particularly cold day, despite a heated habitat and higher protein diet, Silky was found "huddled in the corner of her cage," the news release said.
OHS Animal Care Technician Selene Mejia decided to give her a custom-sized sweater "to help her stay cozy" on especially cold days.
Read the full story from ABC News.