The students

Your infrared camera shows three large heat signatures behind a large, cuboid container-- a human refuse receptacle, apparently. Though the scent of fermenting organic material is pungent, it cannot mask the more pertinent aroma of human sweat and sexual secretions from your sensors. Indeed, the formation of the three probable humans-- one standing tall as the other two kneel close by, subserviently-- is a telltale sign of lust-activity. These three will be easy to convert, and be made subservient solely to the Machines.

A deep-pitched (likely male) voice rings out during your furtive approach: "Oh god, oh yah, oh yah!" Not a moment later, the sex scent quadruples in potency, and is followed by multiple rhythmic exhalations of a slightly higher tone:

"Oh wow, that was a big load, Jimmy! Hehe..."

"You said it, Lisa! Hehehe..."

Now might be an apt opportunity.