mouse in the house

Yes, that is right. My husband went downstairs after work yesterday to discover mouse droppings in 2 different corners of our play room. Then I mentioned that I had seen something earlier in our laundry room, but thought that is was dried up rice. Well, I was very wrong. He went to that place, which was a stack of old sheets, and shook it a bit. Well, what do you know. Yep, mouse droppings came falling out. But, not only that, he also saw a mouse tail sticking out from the sheets. So he quickly took the stack of sheets and threw the whole stack outside in our -30C weather. Hopefully the mouse froze or we may have more problems. But, then who knows, there might be more. I sure hope not.
We had found some mouse traps in our house just after moving in. So we asked our landlord about it and he told us that they had found one mouse about 1 month ago. They had gotten an exterminator and "gotten it cleared up." Well, I guess that isn't the case. And it would have been nice to find out prior to moving in, because we probably never would've moved in to begin with. Well, next time we have to move somewhere I guess we should ask if there are any mouse problems.
If anybody has mouse experience and can help us out here, that would be great.