This happened a while back, study hall in 8th grade actually. I always brought two small sandwiches to school so I could have one at lunch and one in study hall since our teacher let us eat in that class. One day as I was about to eat my Sandwich, I get up to use the bathroom. As I walk back in the classroom, I see the kid in front of me eating my sandwich. I was pretty annoyed but nothing serious at this point, so I confront him politely and he denies it completely. I left my sandwich on my desk the next day just to make sure it was him, and what do you know, it is. So on the third day, I hatched a plan. I put habanero cheese on my sandwich, and then doused it all in ghost pepper sauce. That shit was everywhere, but it luckily didn't smell spicy. I get to study hall and my plan works flawlessly. I leave my trap sandwich on my desk and get up to use the restroom. This time I take as long as I can, and end up wandering the halls of the school. I did this because my study hall teacher was anal about the hall pass, and only one guy was allowed to leave the class at a time, even for water. After about ten minutes I come back into the class to be greeted by the sandwich thief crying hysterically with a bright red face waiting for the hall pass. He was in the bathroom for the rest of the day.