Prince George is a little bit of a rascal - William

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Media captionPrince William: "We were happy to show him off to whoever wanted to see him"

The Duke of Cambridge has described his new son as a "little bit of a rascal".

In his first interview since the birth of Prince George on 22 July, Prince William said he and the Duchess of Cambridge were enjoying their new role.

"He either reminds me of my brother or me when I was younger, I'm not sure, but he's doing very well at the moment," he told CNN.

He also said his son did not "want to go to sleep that much, which is a little bit of a problem".

The duke admitted he does not get up in the night to see to the baby as much as Catherine, adding that she is doing a "fantastic job".

Prince William said he believed fatherhood had changed him already.

"The last few weeks for me have been just a very different emotional experience," he said.

"Something I never thought I would feel myself... it's only been a short period, but a lot of things affect me differently now."

'Wasn't screaming'

Prince George, who is third in line to the throne, was born at St Mary's Hospital in west London.

Image caption Meet the world: Prince William said they were happy to show off their son

The world's media had been camped outside and they got their first glimpse of the new prince the following day when he emerged in the arms of his parents.

Asked about that moment, Prince William said they were "happy to show him off to whoever wanted to see him".

"I think I was on such a high anyway," he said.

"As any new parent knows, you're only too happy to show off your new child and proclaim that he is the best-looking or the best everything.

"It's nice that people want to see George, so I'm just glad he wasn't screaming his head off the whole way through."

After the photo call, Prince William drove his family home to Kensington Palace, and he admitted he had practised fixing the baby's car seat into the back of the car.

Image caption Tried and tested: Prince William admitted to practising the car seat manoeuvre

"I know there's been speculation about that. I had to practise, I really did. I was terrified that I was going to do some... you know, it was going to fall off or it wasn't going to close properly," he said.

"So, I had actually practised with that seat, but only once before."

The prince said driving his family away from the hospital was "really important" to him.

"Where I can be, I am as independent as I want to be. And same as Catherine and Harry," he said.

"We've all grown up differently to other generations. And I very much feel if I can do it myself, I want to do it myself. And there are times where you can't do it yourself and the system takes over or it's appropriate to do things differently."

He also said the couple's black cocker spaniel was "coping all right" with the new addition to the family, and spoke about his return to work as an RAF search and rescue pilot.

Image caption Prince William was being interviewed about his passion for wildlife conservation

The prince has been based on Anglesey since 2009 but is due to leave next month, when his military posting on the Welsh island comes to an end.

Although Prince William has been seen on a number of occasions since the birth of Prince George, Catherine's first public engagement will be at an awards ceremony for wildlife conservation charity Tusk Trust in September.

The duke, who was being interviewed about his passion for wildlife conservation, said it was something he would like to pass on to his son.

But he joked that this could wait until George was older. "At the moment, the only legacy I want to pass on to him is to sleep more and maybe not have to change his nappy so many times."

The interview formed part of a full hour-long documentary - Prince William's Passion: New Father, New Hope - and is to be broadcast on CNN and ITV in September.