Where have all the mice gone? Long time passing

i wish that worked. i have had two professional companies come seal the house to no avail. they even went up on ladders to close anything at the roof line.

 

everyone says our bird feeder is a big problem, but we love watching the birds and won't give it up

 

$6.59? that's above my pay grade

 

57 cents, i suppose you get what you pay for though

 

Agreed. The exclusion is the only answer for our rodents problems. But finding the entry holes and sealing all of the on our old farm house is such a challenge. I spent most of the summer trying to seal as many of those potential entry points, but they are still finding the way in. I wanted to try a professional exterminator this year... but from people having similar problems I talked to, those pros do the same thing as what I have been doing DIY, and charge $$$ for their expertise. I have increased number of traps to ~30 now, and the less and less mouse being trapped. I have had streak of zero mouse in trap for 4 days now. I am hoping they will finally give up.

 

Maybe a smoke generator?

 

fill your whole house with smoke and look for escapees?

 

I thought about using ozone generator. But moving all pets (8 cats) and plants as well as human out of the house for the duration of treatment would be too much. Besides, mice lives in attic and in between walls. We can hear them... I don't know how effective ozone or smoke would be if it originate inside house.

And even if I succeed in driving all mice out of the house, that still is only temporally solution. Without sealing every single point of ingress, we are going to just have new mice moving back into the house in no time.

 

Where there's smoke, there's egress?

A trick that worked for me, looking for egress points from our crawlspace to living quarters, was going around shining a light at the crawlspace ceiling nooks and crannies, while my wife looked for light coming through. Found drywall stopping an inch or so short of the sill plate, one spot behind the furnace, and smaller but big enough gaps on stair risers.

The main egress, from the outside:

In the video, he's thinking "that's funny, I used to get in here...".

The more greyish zones are just patched. These were through-the-wall voids. Behind it is a slab-on-grade, and to the left, a perpendicular grade wall separates the slab from the crawl space below living quarters. That wall stops 8" short of the wall showing in the video, and the fill under the slab spills through that gap, into the crawl space.

Basically, the mice would go through those (patched) voids in the perimeter wall, then turn left under the slab (which is basically cantilevering, has generous space under), through the aforementioned 8" gap into the crawl space, and so on.

 

Yeah, if we had exposed foundation plus wall studs and sill plate, like most house basement does, your suggestion of looking for light will work. The problem is our ground floor (you could call it basement, but it is really a bi-level house or raised ranch ground floor under grade in one wall, and half under grade in two walls and above grade on one wall) is completely finished. Covered with panelings, drywall and drop ceilings. There is no exposed external walls, studs, sill plates visible from the inside of the house. There is no obvious holes on inside walls. I know mice are entering from a small gaps in exterior sheathing, but that is also covered completely by vinyl siding and trims. I don't know if they are coming from the ground level or from the roof line such as soffit on the eaves. I have checked all obvious entry points such as dryer vent, sewer drain pipe penetration point, anything rotting on the door frame or window frame, etc. and closed all I can find, except working on the roof top to see if there are any points in soffit on the eaves, or roof ridge.

Sine they are still coming in from somewhere, I think they are coming from the roof line and entering the house from attic to between the wall, not from the ground. Of course, our attic is filled with cellulose insulation up to my knee. There is no way I can see any point of egress (or any light penetrating through) from inside of the attic.