Not really between the flats. You have lathe and plaster walls and mice can kick about behind the lathe. You will get them everywhere. If you live in Govanhill you get bedbugs or in Pollockshields you get roaches. The only reason I know this is I've worked in hundreds of tenements. You can seal the gaps of the floorboards or get mouse molding for the skirting but you won't ever stop them.
Hope this helps |