interesting. I did not know that. But I'm assuming the mice and rats got in the house? I would imagine that everyone tries to get mice and rats out of the house and don't let them stay...?
I have had mice in every house I ever owned. Either I have a mouser cat or I put poison out. This Fall I found droppings in my kitchen drawers so I knew it was time for poison. That b*tch had babies in my living room tv cabinet. I found her dead when I came home from work in my living room and the babies started to smell and then I found them a couple days later. When I see droppings I empty everything out from my kitchen and use bleach to clean. So far no Hanta virus.
In a farm house I had years ago we moved in and watched the mice go from one heat register across the living room to the other heat register. Could hear them at night in the walls. We got a barn cat a couple days later, Norman, every couple days he left me a dead mouse next to the bed. Such a great guy...he got hit by a car and is dead now.