From wildebeests to the Monarch butterfly, massive animal migrations are impressive and a popular bucket list sight to see.
But one migration you may not have heard of is Christmas Island's red crabs - 45 million of them scurry to love nests while billions of ants with 'crazy' in their name try their best to stop them.
WATCH: Turtles on Christmas Island battle against pollution
Sensitive to not impede them on their journey, the island has several bridges and tunnels so that they don't become red smears on highways.
The migration normally takes place in October or November, and lasts between nine and 18 days, so if you want to tick it off your list you'll have to plan very well.
QUICK GUIDE TO INDONESIA: Visa-free travel for South Africans
How to get to Christmas Island
Near the island of Indonesia's Java, Christmas Island is an Australian territory, so you'll need the same visa as the mainland.
You can opt to fly either from Perth with Virgin Australia, from Jakarta with Garuda or from Kuala Lumpur with Malindo Air. Flights don't take place every day so plan accordingly, and it's advised to add in time for delays.
QUICK GUIDE TO AUSTRALIA: Red outback sands, colourful reefs and modern cities
Find Your Escape by signing up for the Traveller24 Weekly Newsletter – Subscribe here. Or download the News24 App here, to receive expertly curated travel ideas and deals directly to your mobile.