Couple Ideas for you:
1.) Read up on the state laws (if you\'re in the States, I have no idea about elsewhere in the world). In some states, it is illegal to cut down the state flower, so plant them in the middle of the football field...hehehe, they cannot legally get rid of them.
2.) Get nine pigs, number them: 1,2,3,4,5,6,7,8,10. Then get a recording of a pig squealing and hide it somewhere where it is barely audible. They\'ll find the nine, and think there\'s anothor one somewhere.
Ah, so much fun...
Xirius