The girl group are expected to premiere their first single proper within the next few weeks and are currently shooting the accompanying music video.
Speaking in the latest episode of The Little Mix Diaries, Leigh-Anne Pinnock explained: "I think it's going to be a big shock because no-one really knows what to expect yet.
"No-one really knows who Little Mix really are. But with our first single it's going to be, 'BAM, we're in the building'."
Asked if they wrote their new single, Pinnock answered: "We co-wrote it, yeah."
Jade Thirlwall added: "It's perfect. We are so excited to show everyone who we are, but it's still a little bit scary as well."
It was recently announced that Little Mix will support JLS for their upcoming 'Sound City Summer Tour'.
Watch the third episode of The Little Mix Diaries below: