A well-known fact among essential oil users is that rodents hate the potent smells of peppermint and lemon citrus essential oils. A well-known fact among diatomaceous earth users is that DE is highly absorbent. But what most people don't know is that when you combine DE with these essential oils, you create the most potent natural rodent repellent in existence. It works on mice, rats, voles, moles - even rabbits - and it's safe, nontoxic, humane, and smells great.
People have been using essential oils on cotton balls to ward off rodents for years. Diatomaceous earth with essential oils accomplishes the same goal, but it's far more efficient. The absorbent nature of DE makes it capable of holding onto the oils and their scents far longer than cotton balls, which means that using DE will allow to you conserve your oils (and your cotton balls).
Here's how to make your natural rodent repellent:
Add essential oil to water and stir thoroughly.
Slowly add 1 cup of food grade diatomaceous earth to your water/essential oil mixture.
Stir thoroughly until all the diatomaceous earth is moist.
Place mixture in your container.
Place your diatomaceous earth mix as close as you can to where rodents live and eat. If they live in your yard, you can dump it down their holes. If they are in your home, leave your container of scented DE open on the counter or floor where there is a problem. Just so you know, DE mixed with these essential oils won't harm rodents, but it will overpower them with a smell they can't stand, making them want to pack up and leave the neighborhood.
Your scented diatomaceous earth should maintain its potency much longer than cotton balls, but it will eventually fade. Fortunately, it's easy to get it back. If you add a little water and shake it up, it will bring back the scent to about 70-80 percent of what it was originally. Mix another drop or two of essential oil into the newly wetted DE, and it will increase the potency even more. Also, be sure to store scented DE that you aren't using in an airtight container as this will help the scented diatomaceous earth retain its potency.