Today, a red herring refers to a deliberate misdirection. Red herrings were used in hunting by poachers. Poachers would drag a red herring across the path between the prey and the hunting party. The scent of the herring would throw off the dogs, since the smell of fish was often used in training hunting dogs. The first use of red herring as a misdirection appeared in the Liverpool Daily Post of 11 July 1884:
The talk of revolutionary dangers is a mere red-herring.