I have already posted a little about diatomaceous earth. This post is going to be about how to use diatomaceous earth to protect your food. I will fit in a little about other ways to protect your food as well.
I like to use hardware cloth to keep out rodents. It is a lot tougher than wire screens, so they can't get through it as easily.
If you are making raised garden beds, you need to put hardware cloth on the bottom, before you add extra soil or even think about plants.
If you absolutely cannot afford hardware cloth you can put pieces of broken glass down deep so the rodents will cut themselves. I hate this method and it make become a risk to you and others later.
Your root cellar really needs to be protected against rodents. Even if everything is safe in glass jars and cans, rodents can contaminate and carry disease with droppings. If you have barrels of apples and potatoes, etc., those can become a rodent haven.
Pick hardware cloth to line your root cellar with that is smaller than you think you will ever need. You do not want a surprise to find they can get through smaller holes than you thought. We can also expect new species of rodents to invade new territories. You could get smaller rodents than you were used to.
You need to be fanatical to make sure there are NO GAPS in your hardware cloth. Cover vents as well, even small pipes and areas around the pipes and vents.
Put diatomaceous earth into food that could be infested by insects. If you are not aware of this, I have to inform you that there are already insect eggs in most of your food. This includes everything from dry pet food and grains, to prepared foods that are ready to put into your toaster.
Once any insects hatch from eggs in your food, they will die as soon as they eat any food with diatomaceous earth in it.
This post is getting too long so I will continue it.