#2 Son, in the back seat of the car: "What was that I just saw run across the road? I just caught a glimpse."
#1 Son: "I think it was a chipmunk."
JWR, at the wheel: "To be precise, that was a Lesser Western Black Deathwish Chipmunk."
#2 Son: "How can you tell the variety?"
JWR: "Ah! Good question. The Deathwish subspecies nearly always starts to cross the road but then displays its second thoughts by stopping and rushing back from whence it came. Their odds of making it across a road are slightly better than playing Russian roulette."