Common brown garden slugs are usually tan to gray-brown in color, and range from a couple millimeters long to over an inch, depending on the age of the individual slug. They eat plants, with impatiens and lettuce being favorites. Although normally nocturnal, if a day is reasonably cloudy, not too hot, and the ground rather damp (just after it's rained, or just after you've watered), slugs will arrogantly saunter out of hiding and crawl around like they own the place. If there's only one or two, you might get lucky and be able to get rid of them by killing them immediately; otherwise, use a poison. For light to moderate infestations, Slug Magic, which affects only slugs and snails, is good, although it needs repeated applications, especially after a lot of rain. Slug Magic is biodegradable and causes slugs to stop eating, so they starve to death in a few days. For heavy infestations, you'll need something stronger, which will likely have the unfortunate side-effect of also killing all other insects who come into contact with it, including ladybugs, earthworms, spiders, ants, etc. There are several varieties of this type of poison available. Be very careful when buying nursery plants, as slugs can hitch rides to your garden by squeezing themselves into tiny spaces between the soil and plant. Signs you may have slugs are stems turning brown and looking 'pinched' near the base, or the whole plant abruptly turning very light green.
