Photocell for Bangalore Bird Scarers.
The very earliest Bangalore Bird Scarers used photocells to detect when darkness had fallen and to turn the Bangalore off for the night.
A faulty photocell might start your bird scarer up again during the night. A new photocell is very easy to replace.
Note: Photocells were only used on the very earliest of Bangalore Bird Scarers, before even the Bangalore 2000. If you’ve got one of these models, you’ll know!