The kasayadoshi supports a fungus in its body, giving rise to the mushroom-like tail that has earned it the common name “sporetail.” It's believed to live in great colonies together with its young, which are known as sporetail pups. When their territory is threatened, the beasts can coordinate their attacks against intruders far more effectively than any other rodents, a skill which some attribute to a special communication network akin to the mycorrhiza between fungi and plants.