The dancing kids run amok in the library. And give ant and Dec a run for their money in the moves department during Let's Get Ready to Rhumble! See more from Britain's Got Talent at http://itv.com/talent SUBSCRIBE: http://bit.ly/BGTsub Facebook: http://www.facebook.com/BritainsGotTalent Twitter: http://twitter.com/GotTalent Download the BGT mobile app: http://bit.ly/BGTapp Watch full episodes on ITV Player (UK ONLY): http://www.itv.com/itvplayer