It's been well-described and well-observed in primates, but you also see it in rats, and wherever you find it -- humans, primates, rats -- you find it associated with things like tickling.
在灵长类动物身上 得到了很好的观察和描述， 但你也可以在老鼠身上观察到， 而无论你在哪发现了它—— 人类，灵长类，鼠类—— 你都会发现它们是伴随着「挠痒」之类的活动。