Ants...
I was once renting a place when after a day or so I noticed large columns of ants marching all over the place. I followed them to the point in the wall that they were entering from whereupon I gave about a four foot radius of the floor of that point a damn good dousing with the type of insect killer that no only kills on contact, but will also kill any creepy crawly that crosses that bit of floor for a fortnight.

I was not bothered again.
(Woodlouse say it with flowers. Send her a Triffid, Sun 25 Dec 2011, 19:03, Reply)