The cast of new movie musical Cats are taking kitty lessons to perfect their moves in the film.

Taylor Swift, Sir Ian McKellen, Idris Elba, James Corden, and Dame Judi Dench are currently shooting the adaptation of Andrew Lloyd Webber's hit musical in London, and castmate Rebel Wilson reveals they all had to take cat classes as they prepared to get into character.

"It's pretty interesting to be a cat all day," the Australian star tells talk show host Ellen DeGeneres. "We're doing a lot of... cat stuff.

"It's based on the stage musical Cats, so I just thought about singing and dancing part, not about actually being a cat every day."

"It's cool, they have a litter box on the side," she jokes. "We do have to go to cat school though, which is where we just pretend to be cats together. We have a lady, called Sarah, who teaches us."

Rebel needed more help than most of her co-stars, because she hasn't spent a lot of time around pets.

"I'm allergic to cats and to dogs," she explains.

But she insists all the hard work behind the scenes on director Tom Hooper's ambitious project is going to be worth it.

"It's going great," she adds. "You guys will see it for Christmas this year."

Bridesmaids star Wilson portrays Jennyanydots in the film. Her character is a lazy cat, who as per the original story based on Old Possum's Book of Practical Cats by T. S. Eliot, spends her days lounging in warm and sunny spots but teaches the mice how to knit and crochet at night.