translation.en: When one ant touches another, it's smelling it, and it can tell, for example, whether the other ant is a nest mate because ants cover themselves and each other, through grooming, with a layer of grease, which carries a colony-specific odor.
translation.zh: 当一只蚂蚁用触角在接触另一只蚂蚁，就说明它在嗅它。 并且蚂蚁可以分辨气味。比如说，对方是不是同一个蚁穴的。 因为蚂蚁区分其他蚂蚁是通过 涂抹一层带有蚁穴特殊气味的油脂。