I bought Yesterdays News because my local SPCA recommended a non clumping cat litter for kittens just incase it accidentally ingested some. The problem I quickly discovered is with the cat urine, it flows to the bottom of the litter pan eventually and will ferment producing a foul amonia smell. There is not a way to rid the litter box of the litter that has been urinated on. The only thing to do would be to dump the litter frequently and start fresh each time roughly every 3-5 days?