Why Do Worms Die When Salt Is Sprinkled On Them?

Why Do Worms Die When Salt Is Sprinkled On Them?

Salt Sprinkled On Worms

Worms are considered to be some of the most useful animals in the world. They can be used to cultivate soil and grow plants, as well as help with waste disposal by composting organic waste. When you sprinkle salt on worm castings or worm manure, you kill many of them instantly and stop them from reproducing, but how and why?

Quick Answer

Let’s delve into detail about this interesting question.

What Is Osmosis?

Osmosis is a process of diffusion through a partially permeable membrane from a solution with a low solute concentration to one with a high solute concentration.

Osmosis is not to be confused with the process of diffusion, which is the movement of molecules from an area of higher concentration to an area of lower concentration.

Osmosis is the movement of water molecules across a partially permeable membrane from an area of low solute concentration to an area of high solute concentration.

What Does Osmosis Have To Do With Salt On Worms?

When salt is sprinkled on wrms due to a characteristic property of salt, their skin dries out due to osmosis. This also leads to their shrinkage and hence they die! However, salt at a lower concentration would not cause mortality but may reduce reproduction.

Some other species of worms like earthworms, are capable of regulating their water content across the skin; they do not dry out unless salt is sprinkled heavily.

Earthworms ingest soil and digest organic matter in the soil. This process produces worm castings, also known as worm manure, which is one of the best fertilizers for plants.

Sprinkling salt on worm manure or worm castings prevents them from further processing the soil, thereby killing the worms inside.

Why Do Worms Die After Being Sprinkled With Salt? 

We answered this in detail above, but we’ll go over it again.

The main cause of death is the drying up of the worms’ skin as a result of osmosis. The process starts when salt is applied to worms which react with water inside the worms, causing the water in the skin to move out to the worms’ body.

This results in the drying up of the worms’ skin. Since their skin dries up completely, their body shrinks, and, therefore, they die.


The main cause of death is the drying up of the worms’ skin as a result of osmosis. This may also lead to reduced reproductive ability. Also, the ingestion of large amounts of salt may affect the ability of the worms to take in nourishment and to get rid of wastes.

This may result in the death of the worms. If the worms are kept in a very salty environment, they may die. In such a situation, it is advisable to soak the worms in water so that they are able to get rid of the excessive salt in their bodies.

DrWorm - Vermicomposting enthusiast and avid worm researcher for the last 25 years. Interested in what earthworms eat and how to farm and breed them. His garden wouldn't be the same without the help of mother nature's finest fertilizers!