Our club actually used to put on a full-moon moonlight ride as a fund raiser. They would mark the entire trail in glow sticks and crack them just before dark. The horses would actually start going from glow stick to glow stick once they got the idea. Someone put a glow stick on their dog to keep track of him, too. You can imagine how confused the horse was when he walked up the the next glow stick on the trail, and it ran away!