It's day six on the set of Green Porno and star Isabella Rossellini is having sex with a snail. Which is OK, because she is a snail too. After all, this whole bizarre set-up was her idea.

Commissioned by Christopher Barry, vice-president, digital media and business strategy for US cable network the Sundance Channel, Green Porno is a series of one-minute films conceived and written by Rossellini for the so-called '3rd screen' - hand-held video players such as mobile phones and video-enabled iPods.

Each film features the award-winning Blue Velvet star enacting the mating rituals of various insects and garden-variety critters - bees, flies, spiders, dragonflies and earthworms.

The concept is simple: Rossellini dresses up as a male bug and then - imagine naturalist David Attenborough on stage at a burlesque show - describes the action while she engages with a human-scale model of the bug's female partner (except in the case of snails, which are hermaphrodites).

The reality is something else entirely. Production designer Andy Byers has laboured lovingly over Rossellini's costumes and the models. Created from craft-store products - green cardstock is cropped, woven and glued to create the carapace of a praying mantis, for example - his bugs are works of art.

"Ever since I was little, I've always been fascinated by animals, especially in the ways they are like us," says Rossellini during a break between scenes. Her father, the late great Italian auteur Roberto Rossellini, encouraged her interest, buying her books on animals. As a teen she assisted on his science documentaries, and has since collaborated on other nature-themed films, including an episode of the US documentary series Wildlife Survivors in which she explored the animal life of New York's Central Park.

Produced by Rick Gilbert and Rossellini, three initial shorts were directed by Rossellini while five subsequent films were co-directed with Canadian film-maker Jody Shapiro, who shot and edited Rossellini's first 3rd screen project, Oh La La.

The first three Green Porno films premiered at Sundance, and others will premiere next month in the Berlin film festival's Forum sidebar. All eight will be broadcast on the Sundance Channel, which says it will make the films available online and for download in the spring. International sales will be handled by Charlotte Mickie at Maximum International.

Back on the set, Shapiro orders Rossellini into her snail shell for the climactic intercourse sequence. Sheathed in fabric, the arms of unseen assistants poke the actress as she moans in ecstasy. Who knew that snails use barbed probes to inflict pain on each other before the moment of mutual penetration' Viewers of Green Porno will be given a biology lesson that carries a measure of titillation.