It's not just the dazzling colours and slick moves of Australia's dancing spiders that make them special.
There are more than 100 different species of the peacock spider, whereas most animals have only five or ten.
Researchers believe that's partly down to the spider's 'dark DNA' - a mysterious part of the animal's genetic code, and they are studying it to find out more.
They think that this dark DNA might enable it to adapt rapidly to changing environmental circumstances by developing into new species.
What the scientists find out, they say, might help to explain why there is so much variation in the natural world.
