How do the streetlights turn on automatically at night?

@moneymind (10524)
Philippines
February 18, 2007 1:35am CST
On the Flintstones, a small bird sits inside the light and turns it on every night before he goes to bed. In a modern streetlight, How do the streetlights turn on automatically at night? greetings. : )
2 responses
@shilpaum (1753)
• India
18 Feb 07
In a modern streetlight, a small circuit replaces the bird and turns the light on when the amount of light falls below a certain threshold.
@aries6484 (279)
• India
18 Feb 07
its because of technology.i think they have kept something in the streetlight that at certain level if it becomes over heat it should turn off automatically.and when it get cooled down for some time it will turn on again.