Mice and airvents

[ss]

Caught a couple of mice in the last week under the floorboards, groundfloor, just moved to this house recently. Apart from getting in through a door the only other access I can see would be the airvents in the brick, it is the louvre stone type on the outside and I havent a clue if mesh or anything on the inside. the `louvre vents` cant be more the half inch apart. Would this be a likely entry point? If so how best to deal with this (externally)to prevent further access, knowing of course I cant just block the vents.

[Dave Liquorice]

It's that time of year, getting cold outside they come in for the warmth. Caught two tonight (so far) in the loft... there is at least one more up there as a trap has just triggered but failed to catch the little beggar.

Half an inch is ample for a mouse. If they want to they can get through a hole that an ordinary ball point pen will fit. They do have to dislocate the plates making up their skull to do that so don't unless they really have to.

Get some fine wire mesh and fix it to the outside of the airbrick. Making sure that there is no means of getting behind it.

[Ian]

Get a cat.

[Brian Gaff]

If you are joined to another house I'd suggest there are voids between them under the floor for the furry friends to get through. Still cannot hurt to put some close mesh behind the facias. I had wasps in mine which is a whole other problem I can tell you.

Brian

[ss]

I did have a cat up until about 4 months ago however that is not likely to prevent them getting in and if they do get back in it would entail lifting the floorboards each time to give the cat access. In fact in my previous house it was the Bl....! cat that brought them in! I do believe mesh as suggested is the better solution.

[ss]

Its detached, I think I need to put mesh on externally as I would have to rip up a lot of flooring to get internal access to the the vents.

[The Other Mike]

Indeed it is.

...and in dislocating those plates the head gets wider and so a mouse cannot fit through a hole 3/8" diameter, although a shrew might.

3/8" diameter is the size of hole more or less universal in mouseguards for bee hives and they work (touch wood) and have been proven to do so for over 100 years. A slot 5/16" high and around 1/2" wide is big enough for a mouse to fit through.

For reference, a BIC biro, presumably the reference for 'ordinary ball point pen' is 8.2mm across the vertices and 7.8mm across the flats, or about 5/16" :)

[ARWadsworth]

As dennis is a mouse not a man then I asume that he has half an inch.

[ARWadsworth]

Looking at the dead mice that I have found in consumer units then as a rule of thumb I expect a mouse to be able to get through any gap that would allow a 1m T&E cable to pass through the gap.