Amber Valletta was like ''sorority sisters'' with Kate Moss and Naomi Campbell.

The 40-year-old supermodel says she formed a close bond with her fellow runway beauties during her heyday on the catwalk and the stars would often pull pranks on each other, much like a college sorority.

She explained: ''There were pods of us - we were like sorority sisters. We had a lot of fun.

''I can't give you any details because we're all sworn to secrecy. But what we did was ridiculous, the stuff you would do if you were in college, like dressing up in the middle of the night and knocking on people's doors. Can you imagine opening your door and Kate and Naomi and I are standing there in wigs and sweatshirts?''

Amber, who has covered Vogue US no less than 16 times, added: ''Christy [Turlington], Naomi, Linda [Evangelista], Shalom [Harlow] and Kate were my crew. And Kirsty Hume and Stella Tennant too ... Stella was hilarious; I remember she couldn't walk in the Versace shoes. When I see Stella now it's like seeing a sister, and the same with the other girls.''

The blonde beauty has since turned her hand to acting, playing Lydia Davis in hit US show 'Revenge', but she admits making it in Hollywood is far more difficult than the modelling industry.

She told the Telegraph newspaper: ''Had I known back then the kind of sacrifices I would have to make for acting, I really don't know if I would have gone for it. It monopolises everything and it's a really tough business. You hear 'no' way more than you hear 'yes'. I'd never experienced that in modelling. You have to have thick skin.''