Calvin's dead butterfly sign

Calvin drew this picture yesterday, and explained it.  I think it comes from all the discussion of road signs and what they tell us, as we talk about all the road signs and what they mean on the way to and from picking Violet up from school.  Yield signs, no passing signs, speed limit signs, stop lights, etc.

These are his words:

"It is a street sign warning of piles and piles of dead butterflies coming up.  If you run over them it will be all bloody and your tires will run out of air.  The butterflies died because they didn't eat enough 'cause there wasn't enough food in the woods."