EDITOR’S NOTE: Check out CNN’s Sleep, But Better coverage during Sleep Week, March 8-14, or any time of year. The evidence is irrefutable — a pile of drool atop a drenched spot on your pillow. As you ...

(CNN) — The evidence is irrefutable — a pile of drool atop a drenched spot on your pillow. As you awake with a start, you might even wipe that bit of spittle still dangling from your mouth. Drooling ...