Why is rodent hair allowed in peanut butter

Are rodent hairs allowed in food?Most likely you will encounter 1 rat hair in about 1,267,000 reese's peanut butter cups.Moreover, how many rat hairs are allowed in chocolate?That is, you have the assurance that the final product isn't going to cause any problems for the end user.Peanut butter is one of the most controlled foods in the fda list;

Fda even allows some amount of rat hair in peanut butter.And in cinnamon, up to 400 insect fragments are allowed per 50 gram sample.