While working as a student on a ward the other nurses would always play some kind of trick on any new Dr starting on the ward. One great trick i witnessed was for a nurse to get a banana roll it in coco powder and put it in a new clean disposible bed pan then go up to the Dr and ask him what he thinks about this strange BM while he is looking the nurse dips her finger into the banana and then puts it in her mouth saying "yep definatley something wrong" , the poor Dr that i saw ran into the nearest toilet to vomit!