We moved into our house in Aug '08, so spiders watered coming in after the harvest as they do...... House is on a farm so these were Monsters - girl in the local hardware shop told me that she never had one since she got one of those sonic plug-in thingies for mice so I tried it (got one for each floor) and I have to say, since that we have not had amy of the big monsters, just the very odd small one, but before that we could have had three big ones in one day, so def worth a try I thnk.
Point to note is that I dong think sonic thingie has had same effect on mice - we've still had a couple !