There are some large old trees scattered around my neighbourhood, some of which unfortunately are hosts to termites. About once a year these pests swarm and since they are attracted to light you can see clouds of them flying around the street lights - time to shut your windows!
My apartment building is fumigated once a year for termites and cockroaches although I opt out of having my flat done because I don´t want any toxic chemicals around either myself or Toby. When I first bought the place, though, I had it thoroughly treated as there was a built-in wardrobe full of termite holes. In fact I had most of the doors removed except for bedrooms and bathroom in order to reduce the amount of wood around. I replaced these doors with archways which I think worked well.
After living here for a couple of years, one evening after the annual fumigation I entered my bathroom, switched on the light (there is no window) and to my horror a cascade of termites flowed out of the ventilation shaft and down the wall like a torrent of water. The ventilation shaft runs up through the internal structure of the building with an outlet in each internal bathroom covered by a shutter.
I switched off the light and slammed the door while I wondered what to do. Evidently the fumigation had disturbed a nest somewhere and the termites were drawn to the light in my bathroom. Eventually I crept back into the bathroom with a can of insecticide spray and a bin bag to tape over the useless ventilation shutter. Having killed anything that moved and swept up the corpses I thought that was the end of the story.
I complained to the administration and my apartment was given a free fumigation, even down to having the skirting boards injected with poison at intervals (this was before Toby came into my life!). So far so good, I thought that was the end of the story, but...a couple of weeks later, when I was using the loo (as you do), I heard a faint sound as if someone were quietly munching some celery. I managed to trace it to the bathroom door moulding and concluded that some termites had escaped the massacre and taken up residence there. They must have crept in the tiny gap between the bottom of the moulding and the tiled floor and were busily munching away and creating tunnels.
I had to have the entire moulding ripped out and replaced, which was not cheap but at least it got rid of them. Thank goodness they don´t like treated wood so at least my parquet floor was safe. Needless to say I have velcroed some mosquito netting over the ventilation shaft opening and that seems to have done the trick as I have had no trouble since.