Christmas Island is crab island. There are around fourteen species of land crab here. The blue crab is spectacular; the coconut crab (also known as the robber crab because it will make off with anything: pots, pans, shiny objects) is as large as a soccer ball and can weigh up to 5kg and measure one metre across.
But it is the red crab, because of its sheer numbers, which cannot be overlooked. It is estimated that each November, at the beginning of the wet season, around 50 million leave the forest, which covers much of the island, and make for the sea where their eggs are laid.
When the migration happens there are crabs everywhere: on the roads (many are closed as a result), on the golf course, in the supermarket aisles, in the cafe; I even found one in the public toilets.
Many kilometres of 30cm high non-grip tin barricades have been positioned so as to channel the crabs away from significant sites: the high school for example.
But many still get through and on my visit it seemed likely that a few dozen would have to be removed from the sports field before the footy could start.
I found crab watching fascinating and, if I listened carefully, the scratch of claws on the tin barricades and the footfall of the sideways-marching red army could be heard: an eerie, slightly unnerving sound.
There were crabs digging a sharp claw into a fallen paw-paw and transferring the fruit to their mouths; crabs fighting over a banana, crabs clambering over and falling on top of one another; crabs being hauled away by larger, technicoloured robber crabs – before being feasted upon.
Eventually, when they all reach the sea (the time taken depends on the moon and the weather) and finish their business – they turn around and head back to the forest. Migration in reverse: all 50 million of them!