Does cold coffee kill snails?
Moreover, will coffee kill snails?
Coffee grounds scattered on top of the soil will deter slugs. When using coffee grounds, moderation is advised. A study in June 2002 reported in the journal Nature found that slugs and snails are killed when sprayed with a caffeine solution, and that spraying plants with this solution prevents slugs from eating them.
Keeping this in consideration, what does coffee do to slugs?
Caffeine in large doses is said to be toxic to slugs and in smaller doses it can slow them down. It has also been noted that the mere smell of coffee deters slugs and snails. In addition, others state that ingredients in the coffee grounds stimulate their mucus production. This would deter them from crawling over.
When you sprinkle salt on a slug, it mixes with the water in the mucus that the slug secretes to help it move around, creating a salt-water solution. If you use enough salt, the slug will lose so much water that it dehydrates, dies, and winds up looking pretty shriveled.