Although running water is still aerated and the cats would probably like it just as much. Yes, I've seen some attractive little rock fountains for indoors. I'll have to check that out. It would depend on the materials it's made out of...nothing toxic to the cats. It would be a lot more attractive than the faucet attachment I saw that is motion sensor operated. It's kind of ugly and the only two faucets I have inside are my kitchen faucet (wouldn't want it there) and my tub (wouldn't work there).
I'd like the sound of a bubbling fountain in the house. My biggest concern would be attracting tree frogs inside again this summer. Last summer my tree frog Esi took up residence inside for six months, and she would have loved a fountain like that. This past week I found an itsy bitsy baby tree frog on top of my dryer...don't know how long it was inside. I put it back outside. I should have taken a picture of it...no bigger than my index finger nail...cutest little thing, but I really don't want another house frog if I can help it. I'm hoping this was a baby of Esi's. I put her out in February and I'm sure she mated and laid eggs somewhere. 
Thank you for the idea. I think that one is a keeper. 
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