Imagine this scenario for a sci-fi movie – a gigantic mutant slug is on its way to destroy the capital of Earth…What weapon would us humans use to fight the beast?! I can’t imagine how the weapon would look like exactly, but it would have something to do with spreading the salt all over the gigantic slug, right?! Everybody knows that slug and salt just don’t go together and definitely that would be the end of a terrifying creature.
But have you ever wondered why does salt kill slugs? There is a short and long answer to this question and I bet you’re dying to know both.
The short answer will be – slugs die from dehydration when salt is poured on them, a body of a slug contains a great deal of water and salt drains that water out of slug’s body when being exposed to it. That’s a horrible way to die if you ask me.
And what about the long answer?
The long answer is – osmosis. Basically, it’s an in detail description of slug’s death when being exposed to salt on its skin and I already feel sorry for a poor creature. Osmosis is a natural biological phenomenon whereby water passes from one region of high water concentration, through a semi permeable membrane to a region of lower water concentration. Salt is a desiccant, which means it absorbs water from things.
The skin of the slug is far more permeable than the skin of most other animals. So, salt on its skin drys water pretty quickly from it. And there the process of osmosis starts. The water from other parts of the slug’s body rush to restore what’s lost and the poor slug rapidly loses more fluid than it can tolerate, and quickly dies from dehydration.
This process won’t happen on humans and most of the animals whose skin is more impermeable and contains less percentage of water in the body, but something similar would happen to plants. Which is good to know in case we get attacked by an army of plants from outer space 😉