I bought a house in the local mountains. The house had been vacant and after finding some mouse droppings I placed some poison pellets to get rid of them. After more investigation I found that under the house (in the build out) there was not only mice but rats. Enough of them that I could see them in their nests in the insulation. So more poison came out and now I think they are gone.

Here is my problem. I see a bunch of tunnels on the dirt floor of the build out. Do the rats dig these tunnels? If I fill them up with cement will they just dig new ones? Is there any way to rid them for good?

Yes, Rats burrow. Yes, you can get rid of them for good, but it will take ongoing measures of prevention also.

For a start, scroll down to the Rodent Control section here:
http://opkansas.org/_Res/Neighborhoods/Property_Codes_and_Maintenance/preventing_rats.cfm

And here's another good instructional link:
Getting Rid of Rats (http://www.metrokc.gov/HEALTH/env_hlth/Rats.htm)

Hope this helps!

Hi,
Your "local" mountain area didn't specify if it's it the United States.
I have used a very, very good rat poisen; but don't know the name of it.
They are small round green balls, about 1/2 inch in diameter; available from Farm Stores, Coops, or even Lowe's.
There is no smell associated with the dead animals, and it's the best I've ever found. There isn't another rat (mouse) poisen that is this description; or at least not in my local area.
As the previous answer said, "yes" they burrow, just like ground squirrels. Best of luck.

Thanks for the answers. The local mountains is in southern calif near big bear lake. I wish I had know about the poison you are talking about because I am dealing with the dead animal smell by using gloves and a mask to find them. As you can imagine it isn't easy or pleasant.

Rikj, Thanks for the link. I will get started with prevention.