Pest deterrents are substances or methods used to keep unwanted insects and animals away from homes and gardens. They can be natural, like essential oils or certain plants, or synthetic, such as chemical repellents. These deterrents work by masking scents, creating unpleasant tastes, or emitting sounds that pests find disturbing. Using pest deterrents can help protect crops, reduce infestations, and maintain a healthy living environment. Common examples include citronella for mosquitoes, peppermint oil for ants, and ultrasonic devices that emit high-frequency sounds to deter rodents. Proper application and understanding of these products are essential for effectiveness.