Stop, go.

In the old days, signals for stop, caution, go were carried out on the railways with posts such as these. Simple but effective.
Fun with pheasants:
Extra 1: "Cock-a-doodle-do"..... oh, wait, I'm a pheasant.
Extra 2: "I'm gonna fly away" but not with rubbish wings like these.

Many thanks to Carolina for hosting the simplicity themed mono monday.