Scarecrow

The scarecrow is made with straw. Alot of farmers use scarecrows to protect their crops. Farmers cannot protect their crops 24 hours a day. Therefore, they came up with an idea to make a scarecrow to protect their crops because scarecrow resembled humans. Birds are not smarter than human. Therefore, birds will think that the scarecrow is a human standing up on the farmland when farmland has the scarecrow. Thus, birds will not eat the crops if the farmland has a scarecrow present. The scarecrow is able to prevent birds from eating their crops, but you cannot use a scarecrow to protect your crops forever because some smarter birds will know that the scarecrow is not humans. Therefore birds can still eat your crops even if you have a scarecrow. However, the chance of crops eaten by birds is minimized.