Diatomaceous Earth is a fine white powder made of the ground up fossilized remains of diatoms (a type of algae). Its 100% natural and it works because at a microscopic level the powder is very absorbent and effectively dehydrates parasites it comes into contact with causing them to shrivel up and expire. It can be used to control both internal and external parasites. Added to poultry feed - daily use can result in fewer worms.Diatomaceous Earth can be used in your chickens dustbath if you suspect they have lice or mites. It can also be mixed with their feed - a good tip is to add a bit of vegetable oil to the layers pellets before mixing the powder in as it makes it stick to the pellets.