One day you gaze at your aquarium and notice a small snail on the glass. It looks harmless enough. A week later the snail has half a dozen companions. Before you know it, the tank is crawling with them.

Where did they come from? How do they multiply so rapidly? What can you do to get rid of them? Anyone who has fought snails knows it is a tough battle, but there are things you can do to keep them at bay