I suspect if HAL had a representative here, they would give a long list of control measures they put in place for mice. If you look behind lounge sofas, wiring ducts, storage areas, panelling, you will see rectangular black bait boxes, there will be thousands of them on the LHR estate. The law restricts some control measures (certain poisons and glue traps) and the presence of young children rules out others. The appointment of a CCR cat would surely help (once we have over- debated the usual kerfuffle as to the correct breed) but some people are allergic to cats, even if others are pretty unkeen on mice. The reason T4 is currently a bit better than other terminals is that because it was closed for 2 years the critters were effectively starved. Which points to the one thing we can all do to help - try and catch any crumbs on plates and try not to be messy eaters.