Of possible interest here is para2, subsection 4, chapter 9 in the Royal and Ancient's Conduct handbook."When alien invasion of the Course is detected, the Club Captain should be contacted immediately. Said Captain should then, using hand gestures, suggest to the aliens that they must clear the green and retire to the rough. If this does not achieve the desired effect, the groundsman and his coarse mower should be summoned."Your etc.,Ralph Mince- Perve, Hon Sec. Glossop Golf Club.
Go on... you want to say SOMETHING, don't you? Post under a made-up name if you're shy!