“Sure, okay, I'll pick up some cat litter. Anything else?""Watch your back, G." Then she hung up.Hero paused in her sobbing to look at me quizzically. "Why does your mom want cat litter? You guys don't even have a cat.""She uses it for..." I searched my brain madly, but all I could come up with was "teaching.""She uses cat litter to teach English?"I nodded. "She's kind of unconventional in her methods."Hero frowned. "But how does she use it?"The girl was relentless when she fixated on something. "Um, when their papers are really bad, she gives them a little bag of cat litter. It's her way of telling them their writing is crap." I laughed. "She's kooky.”