Diatomaceous earth is a silicate powder that punctures the exoskeletons of pests, neem powder is a pest repellent and moisturizes, and yarrow powder is an anti-inflammatory and anti-microbial herb, so it can keep away infection. Eucalyptus globulus and rose geranium essential oils are pest repellent essential oils that are added to the DOG safe version , for dogs older than 10 weeks old. Please note that we do have a CAT safe version with no essential oils. Just shake it all over your pet's body, and rub it in to make sure it gets through the fur. Reapply at least once a month and after baths, or a s needed. 1 pint.