Peppermint oil is an ingredient used in many flea control products such as shampoo, flea collars, and flea dips. The oil has a strong and pleasant smell, but also seems to be somewhat of a repellent to fleas. It is not a pesticide and will not kill fleas directly by contact, but merely acts as a repellent.
Peppermint oil can also be purchased separately and then added directly to the water that you use to give your pets a flea bath. You may also apply a few drops of peppermint oil to your dog or cat’s skin and then rub it in using either a cotton ball or your fingers.
Reportedly, peppermint oil may also have a repellent quality when sprinkled on an object and placed in a room in order to saturate the room with its powerful smell.