If they're actually living inside your walls, you should consult an exterminator. Simple methods aren't going to get the job done.
Though I'm curious. How do you know they're living in your walls? I used to have a problem with ants in my parents' house and it seemed one summer that there were so many ants that they just HAD to be living in the house. It turns out just spraying around the perimeter of the house was enough to eliminate the ant problem.
The spray we used looked like this bottle:
http://www.amazon.com/Excel-Marketing-8150120-Ant-Block/dp/B000QDEQ7Eexcept it was blue. I'm sure it's the same stuff, just a different brand. But yeah, $20 to keep ants out of the house all summer is definitely worth it. Just read the instructions to make sure you're using it right.
my dad just said that they had to be living inside the walls.... they might not be though, i sure hope not. they might be living under the house also so in that case how do i take care of them?