Eggshells are the key, against slugs and snails! It is an even more natural repellent. As early as spring, you can spread them around all your most sensitive, scatter around the plants you want to protect (at their base). This shell necklace will act as an uncomfortable barrier for these gastropods very annoying! Slugs will have a hard time accessing your plants because of the sharp edges pieces of shells. And if they still pass through this barrier, the eggshells will fertilize the foot of your plants for want of getting rid of slugs! The shell of a chicken egg is composed of about 97% carbonate crystals calcium (CaCO3), proteins and minerals such as magnesium, potassium or iron.