That's because dirt never sleeps and therefore a dirt mover must be ever vigilant.

Or he has insomnia.

Or perhaps he is up late.

Maybe, and this is merely a theory, Otto is in fact an earth moving vampire or were wolf.

JHAP
~~~~~~~~~~
"My mind is a raging torrent, flooded with rivulets of thought cascading into a waterfall of creative alternatives."
...Hedley Lamarr (that's Hedley not Hedy)