First Day of School

The students all pause and you can tell they want a treat like one of Pavlov's dogs when a bell goes off.
Or... like Pavlov getting the urge to feed a dog every time he heard a bell...

The activity continues for some time as you tell students to line up and group bassed off of different interests and traits. You hear someone yell "ow!". You turn around and see a student is holding their arm and looking at another student with a frown.