Prince William's children are "very cheeky".The 38-year-old royal - who has Prince George, seven, Princess Charlotte, five, and Prince Louis, two, with wife Duchess Catherine - admitted his eldest kids are very mischievous while speaking with a group of children in Liverpool, North West England, as they showed him the bug hotel they had made and named Buggingham Palace.In new documentary, 'Prince William: A Planet for Us All' - which has been shot over the last two years - one child asked: "Is Princess Charlotte cheekier than Prince George?” William replied: "No they’re about as cheeky as each other. They’re very cheeky.”William also revealed that both his daughter and his wife have mastered the floss dance, but joked it wasn't something they'd like to see him try.He said: "Charlotte can floss. She can already floss at four. Yeah, you don't want to see me floss. Catherine can floss but I can't. It's, it's like a really horrible film to watch me floss."Elsewhere in the documentary, which airs in the UK on Monday (05.10.20) evening, William also joked Charlotte is "trouble".Introduced to three-year-old Pacha during a 2018 visit to Tanzania, he told the youngster: "You look like trouble, you're just like my little Charlotte."William admitted parenthood has changed his "outlook" and added a sense of urgency to his conservation work.He said: "I think you realise a lot more when you become a father."I was quite a happy-go-lucky young guy, enjoyed parties and then all of a sudden you go 'Well hang on a second, there's a little person here. I'm responsible for that person'. Now I've got George, Charlotte and now Louis, in my life. Your outlook does change."And that's why I had to do something, I had to get involved because I really felt that by the time my children were 20, you know 25, at the rate the poaching was at, there may not have been another rhino in the world. And there probably wouldn’t have been many elephants left at all. It really was that urgent and that critical."