Imagine there are two hunters, Iggy and Norgu. They go hunting every day in the forest, looking for deer. They know from experience where the deer usually congregate and how to catch them. They usually bring home a few deer each day.

One day Norgu has a bright idea. If he digs a few pit traps around the forest, he will just have to check the traps every day to catch deer. Norgu decides to dig 3 traps.

Question: Where should Norgu dig his traps? Should he dig them all in a single area or spread them out around the forest? Should he put one in each main part of the forest or only dig them in places where he knows deer like to roam?

After Norgu has dug his pit traps, all he has to do is check the traps every day for deer. If the traps have caught deer, he spend the rest of the day hunting deer. Even if the traps catch no deer, he still has the rest of the day to look for deer. Soon Norgu is catching a lot more deer than Iggy this way.

After a while, Norgu notices that the deer are learning to avoid stepping in the areas where there are pit traps, so he is catching less deer. Then one day Norgu gets another bright idea. Instead of hunting more deer after catching deer in the traps, he can spend the rest of the day building more traps. Then he’d catch heaps of deer all at the same time and almost never have to hunt the old-fashioned way! So he goes out and digs more traps.

However, after a while he notices that his traps need regular maintanence. It wasn’t so bad when he only had 3 traps, but now that he has 30 traps, it’s getting to be quite a big job. He decides to manage his day by checking the existing traps, bringing all the trapped deer home, then fixing all the broken traps. Soon Norgu is a very busy guy. Even if his traps have caught no deer, he still has to spend most of the day fixing his broken traps. Lucky for him, Iggy is still out hunting deer the old-fashioned way so there are still deer to bring home each day. But overall they are catching less deer than they were back when both of them were hunters. It seems like the new traps have made them even less effective than they were in the first place!

In addition, Iggy has stopped looking for deer in the areas where Norgu already has traps, because he assumes that if there were deer in that area then the traps would have captured them. One day, Norgu checks his traps and finds no deer. Iggy checks the remaining areas of the forest and finds no deer. They both come home and declare that there are no more deer in the forest.

Question: Would you really believe that there are no more deer in that forest? Do you think their methods have effectively covered the whole forest? How does Norgu know that all of his traps are still working properly?