Actress Amanda Seyfried believes Hollywood is "full of petty bullies" and has warned those interested in joining the film industry to "watch their back".

She shared: "This industry is just like every other industry. It's full of petty, spoiled bullies, as much as it is full of wonderful, passionate, honest people... you just have to watch your back."

The 29-year-old actress offered her advice to aspiring actors and directors.

"You just have to be headstrong and believe in yourself, and know that there are people like that who will stab you in the back - just like high school," she told MTV, reports femalefirst.co.uk.

Seyfried also proved that she doesn't take the negative things people say to her to heart even though she regularly reads abuse written about her on micro-blogging website Twitter.

"You can't take yourself too seriously if you don't wanna die. So yeah, sometimes I read the feed on Twitter where people are talking about me. I was scrolling one day, and there was something really sweet, like, 'Amanda heart heart' and a picture of me. And then there was, 'All movies starring Amanda Seyfried are definitely going to be awful'," she said.