Ticks and fleas infest our dogs because of two specific reasons, the first is the odor our dogs give off, and the second is through their detection of carbon dioxide when our dogs breathe. The unique combination of essential oils that the bio-collar releases over time work by overwhelming the sense of smell of ticks and fleas, and by impairing their nervous system which disrupts their ability to detect potential hosts, and lastly by causing them irritation upon coming into contact with these specific essential oils, causing them to flee and never return