If you live with a cat, you know you’ve been there. It’s the middle of the night. You wake up feeling like your bladder may rupture, so you stumble half asleep out of bed, plodding dumbly down the hall to the bathroom. Then suddenly you feel it. At first, it seems like maybe just a little moisture between your toes. But as you step down you feel the goo, the glob of wet furry grossness against your bare foot. And you know. You’ve been hairballed.