They've gone out to do different tasks, and the rate at which they meet as they come in and out of the nest entrance determines, or influences, each ant's decision about whether to go out, and which task to perform.
它们去做不同的工作，当它们进出入口的时候， 它们接触的频率决定了，或影响了 每只蚂蚁关于是否出去，去做什么工作的决定。