Flea & Tick Yeast-Free Herbal Internal Powder is an all natural powder to guard against fleas & ticks from the inside-out. By simply adding the daily herbal internal powder to your dog and cat’s diet, this combination of herbs helps change your dog or cat’s odor so that fleas, ticks, mosquitoes & insects do not like the scent or taste of the blood. The odor is undetectable by humans and is loathed by bugs.