Sleep experts are warning the smell of a teenager's room could interfere with how well they sleep.

A teen sleep study is being carried out at Oxford University to find the best environment for a good night's sleep in terms of how well ventilated it is, the temperature and how bright it is.

The study is also looking at whether teens - aged 14 to 16 - do better academically if they delay the time they start school at in the morning. 

Susan Keogh has been speaking to Doctor Chris James Harvey - Education Officer at Oxford - about the study.