3rd rear was the "ground zero" 'for our bedbugs problems that started 3 years ago.
We have eradicated them from all bedrooms, but could not eliminate them from 3rd rear, even though the exterminator was there a half a dozed times!
We finally threw in the towel and hired a pest control company that brought in a huge heater, and "cooked" the room to above 120 degrees. Adding to the task was having the sprinkler system shut down for the duration (heads removed and capped), then have the technicians return after the heating process to re-install them.
Hopefully this will be the end of our bedbug issues!