While other creatures hide behind fur, feathers or scales, a banana slug protects itself with its slime. This mucus is both a lubricant and glue, allowing it to glide smoothly over most surfaces while clinging stubbornly to others. Scientists have been fascinated by the substance for centuries. One study found that it could help heal wounds. Another found that it can kill certain types of germs, including viruses and bacteria.
This slime is hygroscopic, meaning it absorbs water from the environment and contains proteins, sugar, salt and primary amine. When it encounters something positively charged, like a rock or tree branch, it clumps together and pulls the surface to itself, much like two clingy socks right out of the dryer.
But the sticky, slick substance also creates problems when it comes in contact with human skin, especially when wet. It can adhere to small hairs and cause minor discomfort. It may even cause an allergic reaction in some people.
But most gardeners want to avoid touching slug slime at all costs, as it can spread fungus-causing organisms and disease-causing pathogens. So they use various tools, including chopsticks, spoons, fingers, tongs, tweezers, pinchers and even trowels. They try to pick them up at night, when the slugs are cool and most active. This may not always work, as other animals—like raccoons—still find banana slugs to be an attractive meal. So gardeners also use barriers, like copper rings and tape, to deter them from entering their beds and pots.