Getting rid of rats/mice (merged threads)

I say rats but first off i don't actually know what it is, i'm just guessing and secondly i *think* there's only one of whatever it is.


Last year we heard rustling & knocking behind the walls in our (1930s) semi. The noise got about, upstairs, downstairs. I heard a fair racket under the bath so went inspecting. I saw nothing but in the end i was able to get at a couple of access points (under the floorboards) - one was under the bath where some of the floorboarding had been removed and another was in the back bedroom under the boiler where there was no carpet and i could lift the board. This was actually in a direct line/run through with the bath location.


The bait i used was that 'The Big Cheese' stuff and i put a couple of snap-traps down at both locations.


I took another look some time later and noted the bait had been moved under the bath but untouched under the boiler.



In the end the noise disappeared ... for months, a good few months. We thought it'd gone totally.


Then in recent weeks we start hearing the scratching etc again. To me it sounds quite large, larger than what i'd expect a small mouse to sound like. It was above the ceiling in the box bedroom sounding like it was turning over and flopping against the ceiling floor as i would hear thud-thud.
Last night it was downstairs and sounded so loud that it sounded like it was right up against the other side of the skirting so that you could almost touch it. I don't know what it was doing but it sounded like it was pulling/scratching/biting through something or maybe my imagination on what it's doing is running away, who knows. The skirting wasn't moving as though it was pushing against it but it sounded that bloody close. I'd hit the skirting pretty hard to see if it'd scurry off but it didn't phase it.


Under our living room floor wont help as there's plenty of water there (problem that we can't remove, only manage). It's a suspended timber floor.

The diner which is where this noise was coming from last night is solid concrete floor and the wall it was behind is actually an extension that was built in 2000 which is the one part of that side of the house that isn't connected to next door.
Speaking of next door - we've asked and they claim to have not heard anything that may be a mouse/rat.



I've looked around the house and can't see any access points but obviously there is one. There's the air bricks but i imagine the holes must surely be too small. Aside from that on the lower level there'll be drains but again i'd have expected the access to those to be too small.


Obviously we want rid of the damn thing. Now if it gnaws through some electrical wiring that might do it but then that'd present its own problem. At a bit of a loss as to what to try.