James Franco once nearly suffered a ''breakdown'' from working with mules.

The 35-year-old actor got ''stressed out'' working with the animals on one movie because they weren't doing what the crew told them to do and had to take breaks a lot more frequently than the actors.

He told Nuts magazine: ''Once I had to work with these mules ... there was a mule-drawn cart, and they have these scenes that normally would be simple.

''But you only have so many takes because the mules will get tired and you can't abuse animals. And then sometimes the mules don't want to just go from here to here - so doing that was stressful.

''I remember the first two weeks, I wasn't sure if what we were shooting was going to work - and I was dealing with these mules and I got stressed out. I thought I was going to have a breakdown.''

However the 'Spring Breakers' star would never tire of acting, admitting he is still incredibly passionate about his career.

He previously said: ''I'm very fortunate because my work is the same thing as what I love.

''And in addition to that, when I make movies, or when I do these different projects, I get to work with all my friends and sometimes even my family.

''And so, in that sense, I'm not working at a job that I'm hoping to get away from. I'm not working, waiting for my two-week holiday. A holiday is not as good as what I do professionally.''