The cheeky chaps reveal their private nickname for The X Factor's creator

Ant And Dec have worked with Simon Cowell for a number of years but still find him a bit kooky.

The workaholic talent show judge, 53, always has lots of projects on the go on both sides of the Atlantic so has to be available 24/7.

‘He doesn’t sleep,’ reveals Declan Donnelly, 37. 

‘He is a bit like a vampire, but I’m sure he’s alright.’

Falling year-on-year ratings for the UK version of The X Factor probably aren’t doing poor Simon’s lack of sleep any good. 

But he continues to work all hours with that dazzling smile.

‘We call him the Prince Of Darkness,’ reveals Dec.

‘I always thought he had vampirific tendencies.’

SEE PICTURES Stars arrive at Simon Cowell‘s 50th birthday party

SEE PICTURES Simon Cowell in Celebrity Smokers: VIPs who love a fag

Rachel McGrath