Sunday, 21 September 2014

More de-mousing

After Jello and us caught 12 mice in under 3 weeks, we decided we needed professional help. Again. For the 3rd time. I wrote here how we pulled up the deck and thought we found the problem: a hole around the casing of a window we didn't even know was there.

The exterminator came, and looked, and found a few things we didn't see. The mice actually come in under a section of deck we did not remove (and who's removal would be VERY tough).
Look carefully
Two things are visible in the photo above.

  1. Where the concrete foundation wall of the house meets the siding of the garage, dead centre of the photo above, the garage siding has been chewed to make it bigger.
  2. About 5" to the right of this, hiding but visible is a grey conduit pipe. This is the wire that leads to the garage.
There's also evidence that the mice are using this as their main entrance. There are trails leading around and over that rock in the middle.

We also found a few other things:
  • There is a 3" standoff between the house siding and the house walls. Heaven only knows if there are ways mice can get up between the two.
  • That window we found is packed around its edges with fabric, mostly dark blue corduroy, ripped from an old pair of pants.
Bits of fabric jammed into the top of the window
The exterminator did a bunch of stuff:
  • He squirted expanding foam into the cracks around the window, including the big hole we found;
  • He put down a bunch of ZP. This nasty stuff, zinc phosphide, is a powder that gets on the mice. When the mice lick the powder off to groom, it turns into phosphine gas and they die within 2 hrs;
  • He put down some pesticide laced winter wheat pellets. 
But because he couldn't access the obvious entry point and seal it, nor access the entire wall to close off the 3" gap, we got no guarantees the mice would stop.

So Jello caught one that night. And so did we, in a glue trap. He caught another the next night...
Hunter pride
...and another the next afternoon. Then we caught another in a glue trap last night. Five mice in 3 days. So obviously, the exterminator's work wasn't successful.

I decided to try to attack the problem from the inside. We went into the basement, took down the suspended ceiling along the problem wall...
Tiles removed
...and cut portholes in the drywall above the ceiling level to access the foundation wall.
A bunch of holes
Along the way we found a dried up, desiccated mouse.
Say cheese
The way the basement was finished, it was difficult to get 100% visibility of the wall, especially in the problem corner. But we did find where the wires come in, a hole big enough for the mice, and a lot of poop.
There's room there
We also found that the expanding foam the exterminator dude squirted in around the window did indeed make it into the house. We found another couple of spots where there were holes, too. So I took some of my own expanding foam and filled everything I could see.
Awkward reaching into tight spots
Did we get everything? I doubt it. Did we get where the mice are coming in? Maybe. Only time will tell. What makes me nervous is that the conduit visible in the top photo above is 5" to the left of where the mice chewed the boards. You can see that 5" to the right of where the wires exits the house is nothing: no means of entrance. So I have to assume that the mice make it between the siding and the walls, then come in via the electrical conduit hole in order for what I just did to work.

Here's hoping.


Anonymous said...

Good luck on getting rid of those mice. Hopefully you're using some steel wool where possible with the expanding foam to prevent them from eating through it. Keep your cat away from that poison!

RyderDA said...

Can't use steel wool as it rusts. On the outside, they used copper mesh. On the inside, I used a pest control expanding foam that has a bitter taste.

Unknown said...

Jello is on a roll! Twelve mice in less than three weeks? It's a good thing you decided to involve the pros in this. They know where to look, and fittingly, they saw the mice's "staging area". Were they able to totally prevent the mice from returning? And yeah, better keep Jello safe from those rat poison. Good luck!

Alta Peng @ Liberty Pest, Inc.