‘Roses are red, slugs are black’...hang on a minute, that’s not how the amorous ditty goes - slugs aren’t associated with romance, surely?

Well brace yourselves for a graphic love scene straight from the natural world on Dartmoor.

When we think of animalistic passion, there is one animal which may not instantly come to mind.

But on midsummer evenings in the ancient wet woodlands of Dartmoor, the biggest land slugs in the world emerge from the shadows.

The ash-black slug measurers up to 30cm long and carries both male and female sexual organs.

In an intimate mating ritual that must be seen to be believed, two star-crossed slugs twist together before two penises protrude.

Each penis is as long as the slug’s body…

Is this one of the strangest seduction rituals in the natural world?

Decide for yourselves, as the clip, from the BBC’s new landmark five-part natural history series, Wild Isles, narrated by Sir David Attenborough, is now available to watch.

Filmed in Britain over the past three years, Wild Isles focuses on the wealth of wildlife and habitat to be found on our isles. The series will be broadcast on BBC Two in the spring.