COFFEE KILLS SLUGS & SNAILS. Make very strong caffeinated coffee, then mix it half and half with water and put into a trigger or compressed-air sprayer. Spray on plants and the ground that snails & slugs travel on. As they move over the treated areas, they take up the caffeine through their pseudopod (foot) and it gives them heart attacks in 72 hours. Cheap coffee works as well as the more expensive sort. I use espresso because it's more finely ground (works better in my machine). I also run the water through the grounds more than once to extract as much as possible. Cheers to the University of Hawaii for discovering an elegant and simple solution to nasty critters.