Can you remember the last time you were really tired? Basically, it felt like it was the most tired you've ever been in your life. Chances are it was after a particularly rough day. Probably a day that was both physically and emotionally draining to the point where you barely made it to your bed before you passed out. Chances are less likely that day included chasing your tail, but that could be the culprit for these extremely exhausted animals who fell asleep - and fell asleep hard. They might want to check for narcolepsy the next time they take...