Feeling crabby?

These Soldier Crabs are feeding at low tide on the sand flats of North Creek, Ballina (the eastern Australian Ballina, not the Irish one). This species is found from Asia to the South Pacific, including along the east coast of Australia. The name is said to come from the way the males of the species form army-like formations as they feed on sand flats (see extra). 

There is some video here on YouTube (not my work, I must add). 

And more info on Wikipedia.