clipped from: www.abc.net.au   
Jennifer Viegas

Male crayfish appear to calm down after watching a fight, according to US research that adds to growing evidence that individuals, particularly males, of many species watch competitive encounters.

crayfish on highway

Across the animal world, viewing such events either seems to stimulate further aggression, or lessen it.

During a typical fight, crayfish approach each other with their big pincers or chelae out as far as possible.

They then go into what is known as the 'boxing phase', during which the "crayfish spend considerable amounts of time pushing and not pinching with their claws"

If nobody backs down, the fight escalates as the crayfish use their pincers to grab at each other. Like wrestlers, they attempt to flip over their rivals or forcibly move them around.

If both competitors are still standing at that point, the fight reaches a final, brutal stage.

During this rarely reached phase, the crayfish attempt to cause physical harm, such as the removal of an opponent's chelae or limb