Sorry, cheese lovers. Swiss cheese holes are disappearing. Even if you're not a turophile--yes, there's a word for cheese addiction--you probably still know Swiss cheese by its iconic holes. Those holes are shrinking because today's milk is too clean, thanks to the modernization of the cheese-making process. This news comes just as science finally figured out how the holes are formed. Most scientists thought the holes were caused by bacteria emitting carbon dioxide. But in fact, the famous marks are caused by tiny bits of hay being present in the milk. As the milk matures into cheese, the microscopic hay particles create the holes. But in the past 15 years, traditional milking methods have made way for a more industrial process. The old buckets of milk in the barn have been replaced by air-tight milking machines designed to keep out all foreign particles. So microscopic air-borne hay particles no longer can find their way into the milk; and neither can the holes. Of course, now that scientists have solved the mystery, they are are planning to recreate the holes by adding simulated hay dust to the milk. Gotta love "big agriculture."