Hello everyone,

I have lingered in the GardenWeb forums for some time but this is my first actual forum posting, so please bear with me.

We live in Toronto, Canada, in a 100-year-old semi-detached house. Since moving in several years ago, we have had what appears to be a mouse problem each winter.

During our first winter in the house we actually saw fresh droppings (in the typical spots) as well as what appeared to be very old droppings in inaccessible areas. We brought in a pest-control company,who put poison blocks throughout the house, including in the space between the floors (accessed through the forced-air heating vents) and in black plastic "feeding stations" throughout the house. We also used foam and / or steel wool to block off any visible gaps in the exterior wall of the house.

We found a few dead mice in the basement that year and there was a bad smell in parts of the house -- especially the basement -- for a few weeks at a time.

Last year, we only saw one dead mouse and only a coupe of droppings, but the smell was far, far worse and pervasive throughout the basement and parts of the main floor. My initial thought was that this was either mouse urine or decaying mouse bodies, but (a) the strength of the smell, (b) the lack of an ammonia odour (it was foul but not acrid or ammonia-like) and (c) the lack of new droppings suggested that it might not be necessarily linked to the mice. The odour did clear up as the weather got warmer outside.

As winter approaches this year, we are trying to prepare for this year's mouse season and dreading the return of the foul odour. I am reluctant to call pest-control again based on what appears to be a lack of success in previous years (if that odour is indeed from mice). I would rather trap the mice and dispose of them (I have no compunctions about killing them) than have them pee and die behind our walls and beneath our floors. Interestingly, last winter, the pest-control folks were very non-committal about the odour (they made comments like "I can't smell too well, so don't ask me")

In addition to the steel wool and foam sealant (which I will reinforce in the coming weeks) and the poison-block feeding stations around the house from last year, we have the plug-in ultrasonic mouse repellents in a few places as well.

One big unknown is whether the mice are in fact coming from the other side of our semi -- in which case there is not much we can do. On the plus side, the folks living there just got a cat -- which might help clear up the problem. (We are allergic and can't have a cat ourselves.)

I would appreciate hearing from people who have had significant mouse smells without actually finding or trapping many mice, and what you may have done about it. Also from people who had mouse issues originating in the other half of an attached house, or who have comments about our proposed approach.

Thanks for reading!