Thermal Imaging - A Mystery Solved
The thermal image revealed a hot spot behind the wall, close to the ceiling. It was 6 degrees centigrade warmer than the ambient temperature of the adjacent walls and ceilings and it was about the size of a small football. With the electricity turned off, we waited for about an hour and ran the camera again with a similar result. Strangely, the size of the hot spot had not increased or decreased and the temperature was steady.........so we ruled out an electrical fault or a smoldering fire!
The crackling sound remained however. At this point we are beginning to think about the possibility of infestation........and eventually the penny dropped.......the size and shape of the hot spot, the steady temperature, the constant sound............a bees nest!
The following morning a quick external survey of the eaves confirmed the constant flow of traffic of busy honey bees into and out of the roof!