In a long term emergency depending on where you live, rats and mice may quickly become a problem. Rats and mice reproduce quickly so you can’t ignore this problem. I suspect you will have more problems in the city or urban areas than in the country. Rats and mice spread disease, destroy food and cause other types of damage. Rats can chew through plastic buckets and even some metal containers.
Now if you have a rat problem there are two ways to look at them, are they just a pest or a source of food? If they are a potential source of food, you have to be careful about poisoning them. I avoid using poisons because you can’t control what animals might eat the poison; you don’t know the effect on the food chain; you can’t control where the rodents will die. We have had to take my sons dog to the vet because he ate a poisoned rat. If you choose to stock poisons, be aware that the EPA is attempting to ban the most effective poisons from the marketplace. Talk to your local feed stores to get the best recommendations on the types of poisons that can be used in your area and stock up now.
If you consider the rats and mice a potential source of future food, you need to trap them. Plus even if you use poisons, you will probably run out. I store a lot of old fashioned snap traps because they are effective, hygienic, and reusable. You can get them in sizes for both rats and mice.
The Victor Tin Cat Mouse Trap, is an effective method of catching live mice, it will hold up to 30 mice at a time and is reusable. It is a box designed to use in large commercial food processers and sells for under $20. Since the mice are still alive, you could consider it a meal in a box. There are some large electronic box traps; I do not recommend them, because they require batteries.
The sticky traps are very effective, but are not reusable, so you have to stock quite a few of them. The best thing I know of for rats is the old-fashioned snap traps, using something sticky for bait. That way they have to work to get it loose and will spring the trap.
A friend of mine who is an exterminator says that Bounce dryer sheets emit a smell that rats and other rodents find very unpleasant. He has kept mice out of his house by placing the sheets across their entry points.
Be sure and check your home or storage area for entry points. One likely spots is around plumbing pipes. If there are small space around where the pipes come through the wall, stuff steel wool in them, this will kept rodents out.
Prevention is always the best solution; keep your area clean and neat. Bury or burn your garbage and avoid leaving out food that will attract rodents.