Mining skills are not the only thing brought to America by Cornish miners. It seems that the Tommyknockers hitched a ride over with their mining pals.

A Tommyknocker is a little elf-like creature, who lives in mines. They have the ability to walk though walls and disappear at will. While they may be mischievous, stealing miners belongings and such prankishness, they are basically benevolent to miners and, while a bit spooky, are welcome guests in the mines.

It has long been thought that the tappings and other such noises on mine walls, on beams, and in shafts are due to the Tommyknockes. Miners have long recognized these noises as the Tommyknocker's way of signaling impending danger to the miners. There are few, if any, mining areas which are free from legends of Miners who have heeded these warnings and been saved from disaster. Some legends go even further and recant instances in which miners in trouble have actually been saved by the Tommyknockers.

If you are ever wandering around in mining territory, and hear rapping coming from inside of a mine tunnel or shaft, you don't need to be scared of the little fellows. It is a good idea, however, to vacate the area you hear the rapping coming from immediately as they might be trying to send you a warning.