There are mice in my house. I can hear them in the walls and ceiling. Or at least I think I can. Luckily I haven't spotted any yet. The joys of an old house, eh?!
UPDATE: I emailed the agency and - apparantly - they put down some traps and medicine for the mice the other day, but they'll come back and check. They also recommended I get some medicine for my ants before they come round to check for where they are coming in, etc.