Organic Rat Poison
This recipe for homemade rat poison is very easy to make. It does not contain anything which is toxic, however, you will need to ensure that your children or your pets do not find it.
Mix equal parts of cornflour with plaster of paris with enough milk or cream to bind into a dough. Roll into balls and place near mice or rat entrances or around places they might visit, like behind the fridge or the stove. This mixture will cause rodents to die just as surely as a toxic commercial bait. A deterrent is a preferable option, however, these are not always effective, especially if the infestation is severe.
Spearmint oil and peppermint leaves and their oils are useful as a deterrent for rodents. Sprinkle a few drops of oil around their pathways or near their entrances to the house.