Greetings! I just 'discovered' this site. I hope I'm posting this in the right forum. "Pest Control" and "Roofing and Siding" seemed like good options, too. Our house was built 62 years ago; we've lived in it for 12 years. It's a ranch with vinyl siding--which was probably originally aluminum siding. We had the basement completed four years ago; my family spends a lot of time there. Last Fall, as temperatures began to fall in the evenings, we began hearing occasional light scratching above the drop ceiling. At first, we thought it was our imagination; one evening, however, we definitely heard something running across the top of the ceiling. We set traps on top of the ceiling tiles; a small mouse was caught. We thought that was the end of the matter--until we started hearing scratching again. Over the winter, we caught about a half-dozen more mice. We're concerned that we still have mice; we're continuing to set traps. We're more concerned, however, with how the mice are getting in. We inspected around the outside of house but didn't see any obvious openings. The dryer vent looks OK and the tubing from the vent to the dryer is made of steel--so it doesn't appear that the mice are getting in that way. An exterminator friend suggested that a mouse might have snuck in an open door--but we think that's unlikely, especially since we're careful with the door...and we're catching additional mice! Using a mirror (to make it easier to view things from the underside), I looked at the area where the vinyl siding meets the foundation. I noticed a few small (1" wide) upward openings in the wood framing--openings that seem to go entirely through! Without any other explanation, I'm assuming that the mice got in that way. I filled the holes with a foam sealant. I'm guessing these openings were created recently but I have no way of knowing. As I understand it, mice can climb and chew through just about anything. On the other hand, perhaps the openings have been there for many years; if so, why haven't we noticed a mice problem before? (We've yet to see any mice--or mouse droppings--in the living areas of the house--but we've seen them on top of the ceiling tiles.) A friend/contractor is suggesting placing long metal strips horizontally, bent at a 90-degree angle, around the perimeter of the house, pointing in and up, where the frame (that the vinyl siding is attached to) meets the foundation. In theory, this would prevent the mice from creating new holes. We're wondering whether this suggestion is sound--or whether a different solution would be better. I appreciate anyone's thoughts on this!