translation.en: But what it does do is to make and secrete small molecules that you can think of like hormones, and these are the red triangles, and when the bacteria is alone the molecules just float away and so no light.
translation.zh: 但是它们会制造分泌小化学分子 你可以把他想象成荷尔蒙, 这里的红色三角形代表这些小分子, 当细菌独处时， 分泌的小分子游离开来,所以不发光。