Julia Roberts wanted to be a vet.

The 'Eat, Pray, Love' actress used to dream of spending her life helping animals, but fell into acting because all her family work in the business.

Julia - whose brother Eric Roberts and sister Lisa Roberts Gillan are actors and whose parents, Betty Lou and Walter Roberts, were at one-time actors and playwrights - said: "I wanted to be a vet. I love animals, but then I discovered how hard science can be. My parents and siblings are all actors, so I grew up around it."

Although she loves her career, the 42-year-old star admits she doesn't think acting is a very difficult skill to master.

She explained: "It's a great way to observe human behaviour and how people react to things. It's like grown-up pretend. My daughter does it all day, I just get paid for it."

As well as showing an interest in animals, Julia is also passionate about the environment.

She told Stylist magazine: "It's probably my greatest concern, besides my babies. My husband and I spend most of the year away from Hollywood in California, where we support Heal The Bay, a non-profit organisation dedicated to keeping Southern California's coastal waters clean. I also drive a biodiesel car and we compost everything. It's a big commitment with three kids, but there's so much valuable waste, you sort of have to."