Before you get up you decide it is best to play dead, you roll onto your back and hang your tongue out. Stay very still and try to breathe very slowly. Several minutes pass and you hear some shouting from beyond the glass. Someone has noticed you. Moments later a small piece of meat falls into your inclosure. The smell is delicious and inviting and makes you realize you are hungry and consider reaching for the food. You also consider the possibility that the meat is there to bait you into moving and prove you are not dead.