Brother:  I can’t eat the rest of my ice cream.

Me:  Give it to the cats, then.  They’ll like it.

Sister:  NO!  Don’t give it to the cats.  It will make them sick.

   Discussion ensues on cat health and cream during which Brother sits his remaining ice cream outside.  Just as Sister is about to make her final point ….

Brother:  Look!  They’re eating it and they’re not dying.

Case Closed.