translation.en: And we've done experiments that show that that's because the longer an ant stays outside, the more these simple hydrocarbons on its surface change, and so they come to smell different by doing different tasks.
translation.zh: 我们做的实验表明， 那是因为在蚁穴外面待的时间越长， 这层碳氢化合物的表面变化越大， 所以它们就因不同的工种而有不同的气味。