My Cat Nimitz used to do that with the Petmate Drinkwell fountain, until I got the Ultimate Bubbler from Petmate. I know, I sound like a commercial, but I have to tell you all, it is the best thing out there. My cat Nimitz would tear open the bag and the activated charcoal would spill out into the water. He would literally knock off the top part of the fountain, and also tip it over to where water was all over my hardwood floor. I think he liked to play in the water, yet he hates it when I give him a bath. I got the Petmate Ultimate Bubbler, and that has never happened since. It has a big resevoir that holds a lot of water, and it produces bubbles from a plastic tube with holes in it that oxygenates the water, and provides a fresher tasting water for both my cats. I think with that product, it is harder for my cats to knock it over or bump it.