Generally, by the time that you realize that you have a rodent problem, they are pretty firmly established. People often see one rat or one mouse in their home and think "I have a rat" or "I have a mouse", but really for every one that you see, there are dozens that you don't see. So, before we talk about what to do, you might have to come to grips with the fact that you may have a lot of rodents living with you right now.
In my experience as a pest control professional, these are the steps that must be addressed to get a rodent population under control. Now, obviously the best thing that you can do is call me at Healthy Homes Pest Control and have me take care of your rodent issue, but for the sake of this article, I am going to teach you how to address them on your own first.
1- Act Quickly! Rodents reproduce at an amazing pace (up to 72 babies a year) and every day that you wait in getting this under control, the problem is getting worse. Also, rodents have no control over their bowel movements and leave fecal matter and urine everywhere they go. This causes two problems. First, they are contaminating underneath your home and up to 40% of the air you breathe comes from underneath your home. Second, as their scent gets stronger, it becomes more inviting for other neighborhood rodents to join in on the fun.
2-Remove Food Sources: Rodents generally are going to make their nests with 10-20 feet of a food source. Maybe this is why they chose your home. Do you have a bird feeder that they might be eating off? Do you leave out cat or dog food? Walk around the outside of your home and through your garage with this in mind. If you find a potential food source, remove it!
3- Check For Entry Points: A mouse only needs an opening as large as a quarter to get into your home, so this could be tough. However, you should be looking for obvious entry points. The most common entry points is from your foundation vent screens. Check to make sure that they are intact, particularly in areas where wires come into the crawl space from the outside (thank you cable guy!). Also, look for burrow holes and cover them up. Rats make a burrow hole as big as a tennis ball and mice make on the size of a golf ball.
4- Set Traps: Ultimately, the best thing you can do is set up bait stations on the exterior, but with a pest control license, you will not have access to any bait that will actually work. So instead, you are going to need to set traps under your home. You will want to do this right away after sealing entry points because they are going to need to get food and you may have trapped them inside. So, you need them to find the traps quickly so they don't die where you can't find them and stink things up. When setting up traps, put peanut butter on it, but do not set it yet. Give them one free meal and once they have eaten the bait, they are more likely to get caught when you set it later (this is especially important for rats).

I hope that this information helps you. If you have questions on anything that I discussed today, I would love to hear from you. Please feel free to leave a comment or give me a call. Again, if you are in the Puget Sound area and just want me to take care of your rodent infestation, I would I love to have you contact me. Thanks for reading!