The watery antics of a curious echidna have been captured on South Australia's Kangaroo Island.

Key points: Footage of an echidna swimming has been posted on social media

Footage of an echidna swimming has been posted on social media An expert says while rare to see, echidnas are actually "quite good swimmers"

An expert says while rare to see, echidnas are actually "quite good swimmers" She said echidnas have a low body temperature and cannot deal with the heat

The footage was taken last Friday by Ben Cobby, of Kangaroo Island Bush Getaway Adventures, during a quad bike tour of Karatta, on the south-western side of the island.

He said while he had seen plenty of echidnas out and about, he had never seen an echidna swimming in the water before.

"We see a lot of animals on our travels doing all sorts of funny things but that one took the cake," he said.

"We see them pretty regularly on our quad bike tours as we ride around and show the tourists.

"But that's the first time I've seen one taking a swim."

Found in 'swimming pools, rivers, even the ocean'

University of Adelaide PhD candidate Tahlia Perry is an echidna expert who is currently studying the monotremes.

She said there was a lot people did not know about the echidna and they were actually "quite good swimmers".

"More and more often we are getting videos sent in finding them in swimming pools, lakes, rivers and even in the ocean sometimes," she said.

An expert says it is quite common to see echidnas swimming. ( Facebook: Kangaroo Island Bush Getaway Adventures )

"Their back feet point backwards, so they sort of have like a natural rudder system with their feet.

"If you watch the video closely you can see the way their feet sort of paddle … then they use their snout as basically a snorkel system."

Ms Perry said echidnas would often swim as the weather got hotter as they could not handle the heat as well as other mammals.

"You do find them in the water quite frequently and especially now that it's getting into warmer months they will be in there more often," she said.

"Their body temperature is lower than other mammals, we [humans] sit at about 37 or 38 degrees and echidnas are usually at about 30 degrees.

"They can't deal with the heat very often and that's probably a reason why you will find them in the water on hot days."

Researcher says echidnas can be 'difficult to find'

An echidna spotted in the river near Ashby Island, NSW. ( ABC Open contributor Cyn Bodycote )

She said the main fact about them was that, along with the platypus, they are the only egg-laying mammals that exist.

"They are quite unique in that sense, they inhabit almost every type of environment imaginable, so you see them in the snow, in the desert, in forest areas.

"But they are quite difficult to find as a scientist, it takes up to 50 hours of fieldwork to spot one echidna, so they are quite good at hiding."

Ms Perry called on others to keep an eye out for echidnas.

In 2017, along with other researchers at the University of Adelaide, she developed a smartphone app which helps collect data on echidnas.

The EchidnaCSI app allows people to take photos of echidnas, adding location details and other descriptions which helps researchers to further analyse them.