While peppermint has a strong, refreshing aroma that works well as an air freshener, it is a scent that is disliked by rodents such as rats. You may be able to deter rat infestations and chase this pest out of your home by using a mixture of peppermint oil and water along rodent entry points and scavenging areas such as food pantries and kitchens. To use peppermint oil for rats in your home, add two to three drops of peppermint oil to a cup of water. Combine this mixture in a spray bottle and then spray suspected rat entry points around your home. In addition to spraying the foundation of your home, use it at the backs of food pantry areas, under kitchen appliances, and in dark or cluttered cupboards to ensure rats stay far away.