One of my two cats passed away last December of kidney failure...a common cat disease. I was told that cats (unlike dogs) do not drink enough water. And if you feed your cats dry cat food, as I do, because they are on a special diet, the lack of moisture contributes to problem. Both of my cats were always in the tub, sink or toilet trying to get water, even tho' we gave them bowls of fresh water every day. Cats prefer running water. I first bought a cat fountain from Walmart - the cats didn't like it because it didn't simulate a faucet, so I returned it. The minute I bought the Drinkwell Fountain, my cats immediately took to it. And I can honestly say that both cats drank much more water. Unlike the first 2 reviewers, I don't find it too loud. You should keep it topped up every day. A couple of tips - it does need to be cleaned once a week, which takes about 10 minutes or so. There is a charcoal filter which needs to be replaced, much like a Brita filter. There is a reservoir where you can put ice cubes on hot days. There is a little lever which lets you control the flow of water - low to high. Follow the manufacturers instructions e.g. don't let the fountain go dry, or you'll ruin the motor. I wish I had bought this fountain years ago and maybe my first cat would not have died from kidney failure.