A gangly-looking motion detector floodlight is fine for scaring ... be at least as high as the total watts of the fixtures.

As an example, [Circuit Valley] has an IKEA Vallhorn motion sensor for a teardown, it’s as you might expect, a passive infrared sensor (PIR) sensor coupled with a Zigbee interface. Inside the ...

If signals are different (for example, caused by different sources), the alarm is ignored. The device automatically increases or decreases the sensor sensitivity in order to accurately detect motion ...