Damp cats is an international slang reference used by road workers around the world to describe a piece of roading equipment that has gotten wet or slightly damp.
The term was originally coined to describe the popular road-division device ‘the cats eye’, but soon spread to mean just about anything found on the road.
There is barely a motel worker in the world who has not heard the distant cry of “DAMP CATS” on a dark, wet night, indicating that someone’s jacket has been left on the road and is getting wet. Or signifying some freshly laid concrete is flooding and may require drying by hand.