If they are too sensitive to light then they 'see' their own light and
switch off.

Not quite - the sensor can be and is ignored when the light has been
turned on to prevent them cycling, besides which there a tremendous
difference between the levels of daylight and that provided by a lamp.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk


Surely it depends on the lamp shade or fitting. Some may keep natural light
away from the sensor.

If the sensor can ignore its own light then how can it detect the daylight
of the morning - I guess it would only be a simple photo cell.