security system is modelled on primitive 'torch systems', used
by ancient peoples to define a circle around their territory,
and warn off other groups and wild animals.
the corners of the garden, the Natural Guards create a motion
detection fields (see diagram) using passive infrared and microwave
technologies, which sense both motion and body heat of humans,
but allows smaller mammals,such as cats and dogs to pass unhindered.
motion sensors are activated the system acts as an advance warning
system - relaying a signal to the alarm inside the house & alerting
the household before an intruder makes an attempt to gain entry
to the building. The intruder is likely to abandon a break-in
attempt if he is warned while still in the yard that he has
been detected by the occupants of the target house.