Turtle Teacher

Every classroom has a turtle in an aquarium, placed on a table in front of each class.
The kids stare at the turtle for four hours, take a break for lunch, and return to staring at the turtle for the rest of the day.
Cameras watch the turtles and students, and the principal watches the video screens.
Nothing happens for days… weeks… months…
The Ministry was ready to pull the plug when an alarm went off in Classroom Twelve.
The turtle was gone, a greasy smear on the inside of the aquarium.
Upon review, one student’s eyes glowed red.
Success!