One of the world's great wildlife migrations will reach a hectic climax in coming days when millions of red crabs make a dash for the water on Christmas Island.
When the tide is right, columns of determined females that have already endured a week-long march from their forest homes will plunge into the shallows.
With their claws raised about their heads, they'll vigorously "shake their booties" like they're in a mosh pit at a dance party, releasing sacks of eggs from beneath their abdomens.
Those eggs will hatch almost immediately and the larvae will vanish into the sea only to return three to four weeks later as baby crabs. In a good year, entire rocky outcrops and stretches of sand can be blanketed in the tiny, scurrying creatures.
It's a reproductive marvel that never gets old for scientist Tanya Detto, who is working to protect the crabs from invasive species including the yellow crazy ant.
"The last six or seen years we've had some amazing baby returns but in the six years before that we hardly had any. It just depends on the weather conditions," she says.
Crazy ants were first detected on the island in the 1920s but it wasn't until the first super colonies formed, in the late 1980s and early 1990s, that they became a problem for red crabs.
"We think the reason they suddenly started causing issues was the introduction of the yellow lac scale insect," Dr Detto says.
The sap-sucking insects excrete a sweet liquid called honeydew providing yellow crazy ants with an abundant food source. To date, the ants have killed tens of millions of red crabs by spraying them with potent formic acid.
Scientists have successfully deployed a micro-wasp to prey on the insect, thereby limiting the crazy ant's food supply. Ant nests have also been baited.
But the fight to safeguard the red crab - which is found only on Christmas Island and to a much lesser extent the nearby Cocos Islands - is not yet over.
About 20 other scale insects are present on Christmas Island, all of them introduced.
The next step is to investigate other potential biological control agents to keep those ant food sources in check.
"There are still areas where the crazy ants are forming super colonies, and they seem to be driven by those other scale insects working together," Dr Detto says.
"We have definitely decreased the number of super colonies out there, but we haven't entirely solved the problem."
Female red crabs are expected to begin their annual spawning from about Sunday, when the tides will be just right.
While she waits for the big event, Dr Detto is busy crunching the numbers from her latest crab census. Fingers crossed the numbers will be up from the last estimate of 30 million to 40 million a couple of years ago.