Earth Animal Nature's Protection™ Flea & Tick Herbal Collar for DogsMother Nature doesn't use synthetic chemicals. Neither do we. Our philosophy is simple and 40 years strong. We believe that dogs and cats should never be the carriers of synthetic chemical insecticides or pesticides. Ever. As seasons change, so does the need for flea & tick protection. Using our team of Nature's Protection products together helps create the ultimate defense for your dogs and cats with 2 easy steps to build immunity and combat fleas