Soldier crabs, Mictyris longicarpus are indigenous to Eastern Australia. On a falling tide you will see them miraculously emerge from the sand forming massive armies of hundreds and sometimes thousand seemingly synchronised as they march together across the sand floats.
When threatened they will burrow corkscrew-like into intertidal muddy sand flats. If you like to see a video of them on the march click here.
If you like to know more go to the Queensland Museum website. Click to go there.