Independent film is for actors that love to act.

I gotta tell, that's one of the things in Hollywood that has not been a barrier. I've gotten lots of offers, and I did try my hand at it, I directed two commercials. I won best commercial of ad week [laughs] on my first try.

You have the hilarity and the great production. These films are distinctive because they are not just topical, they tell good stories and they let scenes play out physically. Apart from the dialogue, the characters also have a non-verbal existence, for example with Scrat.

Voices come to me but to maintain them is hard work. They go away just as easily, so I have to remember them and that takes work. With Sid, I needed to make sure you could understand what he is saying, his enunciation. Sometimes I couldn't even say my own name [his name] in his voice. It sounds like 'Shid', it sounds a bit like he has a lisp.

I had to work with Ben Mendelsohn who's one of the great actors of our time. I had a lot of scenes with him and I was thrilled to be on the set with him; I just wanted to see how we were going to play it.

I love life, and I embrace every minute of it.

But when you are doing an animated voice, it has to have more energy than usual or it falls flat and doesn't work. For myself, I found that I had to put myself in the same physical or emotional state as Sid, in order to make that voice sound alive and authentic. So if there was a scene in which he was running, I would be running beforehand to sound out of breath. That's important because the audience can tell intuitively if it does not sound real.