Hi Marcia, maybe this article will help with the problem.
Snap traps work, they are cheap but yucky. I use an electronic trap, works well and is way less messy. Do not use rat bait, they will die anywhere, you might not find them until you smell them. Also bait that kills rats will also kill anything that consumes that rat. mice will carry bait to the nest, and that could lead to an other animal getting to it and killing them also.
Hi Marcia: I'd avoid snap traps as other critters may get injured or killed in them, like kittens or other little animals. Also, I wouldn't use poisons either. They may kill the rat, but whatever eats the dead rat eats the poison, too, and you may kill someones pet, inadvertently. The best thing to do is to keep the area clean of any food sources that the rats may get into. If you see a hole, put a rock in it and fill it with dirt and pour vinegar over the area.
Here are a couple of sites that should help get rid of them naturally:
Catch and release traps. You don't want the dying and rotting in among your stored items.