It’d been easy to infiltrate the school; slip in during the early hours, follow the first to open a door. After that, map out the facility, then find a suitable vantage point for surveillance.
Initially it perched in classrooms, but gained no information of value; children were not allowed to converse with each other there. No, better to be in communal areas; there children spoke, there they laid bare their psyches, there one could learn what it would take to dominate and control humans.
So it disguised itself as a drinking fountain; recording, analysing, and communicating with the mother-ship.
Some time passed.
Somebody stuck a piece of paper to its chassis, another affixed yellow tape.
One day, a man in overalls set down a box of tools, rolled up his sleeves and pried open the fountain.
They found his body across the hall later, after one of the children screamed.