Screwworm cases have dropped to almost zero since this summer's detection, and everyone who actually knows parasites is uncomfortable with it. "Zero cases in wildlife is unexplainable to me," - Sid Miller, Texas Agriculture Commissioner. Current APHIS staff: "suspicious" and "it doesn't seem very likely." Former USDA officials: "It's very strange. It doesn't make a lot of sense, biologically." Either something extremely effective is happening without explanation, or something else is going on entirely. Nobody wants to say the quiet part.