I've actually used peppermint as BAIT on rat traps, and caught rats! Sure, peppermint is going to keep them away! So is pineapple juice, lady's deodorant, and licorice! Give me a break. The number one search result for rat repellent right now is a bag of corn cob chips and other essential oils, including eucalyptus, grapefruit, sage, and lavender!