But the combined warmth of their bodies and the confined underground space probably negate the problem of losing heat to cold air for these animals, allowing them also to become naked.

• 人类褪掉皮毛从而减少了寄生虫的数量，同时采取生火、建造房屋、逢制衣服的方法避免了在晚上及寒冷的气候中受冻。