the.com/sleepy
the body's gentle bouncer, escorting consciousness toward the exit one yawn at a time
yawn contagionSeeing a yawn triggers yours in seconds
warning systemDrowsy driving rivals drunk driving for crashes
adenosine buildupA chemical accumulates all day, urging sleep
heavy eyelidsCaffeine works by blocking that very molecule
microsleepsBrains nap for seconds while eyes stay open