they bought 3 pigs, painted the numbers 1, 2, and 4 on them, and let them loose in the school. The administrators expected a number 3, which they never found, so they looked around for about 2 hours looking for it.
At our school its a really loyal and funny tradition that the year 11's (as im from england we only have up to year 11's in senior schhol)
one of them or groups of them, a few days or weeks before the end of school for the year 11's, they would run out round the whole school shouting and rioting, and then, one of them will always set of the fire bell, which always makes the whole school go crazy etc, then they would start rioting again, my bro was one of them ;)
i actually find it funny as all the teachers take it so seriously for a bit of fun, even when they know that thats the tradititon of our school, and they know thats whats happening