In nature, moving water is much fresher than stagnant water. The movement constantly breaks the surface tension of the water and draws oxygen from the air into the water. This process is called aeration and it makes water more appealing to drink. Pets may be drawn by instinct to moving water for this reason. The Drinkwell® Pet Fountain filters and aerates continuously moving water to keep it much fresher than a standing bowl of water. It satisfies the urge for running water and so helps eliminate jumping on counters in search of dripping faucets.