What do traffic cameras at traffic lights look like and do they flash or click when they take a picture?

At most intersections, you will see little cameras at the top of the light. They look like little tubes. These are not red light traffic cameras. They are sensors used by the traffic light to control whether its a green light or red light. Actual red light cameras are usually bigger and are placed on the curb on its own pole. They usually have a flashlight to take pictures. They flash at night when taking pictures.