You are starving and have to choose between two pieces of meat that have been sitting out in the same place for the same length of time. One has a few maggots on it, the other appears fresh. Which one should you choose?

Answer:
Pick the one with maggots on it. The flies would lay their eggs on each equally, so they should both have maggots. The fact that one has no maggots suggests it has been poisoned.