‘Secret code’ Kate Middleton uses to keep Prince George, Princess Charlotte and Prince Louis behaving

The Princess of Wales reportedly has a 'secret code' she deploys in order to keep the behaviour of her and Prince William's three little ones in check.

While it's obvious Kate and William aren't handling it all on their own - they will have stellar childcare - the summer holidays are stressful by any stretch of the imagination for any parent.

The little royals, Prince George, 11, Princess Charlotte, nine, and Prince Louis, six, all seem to have massive personalities, and often the public get to see their cheeky side.

George and Charlotte have been known to stick their tongues out on occasion, and Louis has been spotted making funny faces when attending events with Kate - who can forget him stealing the show at the late Queen's Platinum Jubilee in 2022.

The royals are enjoying a summer holiday in Norfolk. (Chris Jackson/Getty Images)

Royal or not, it seems the parents have their work cut out for them with the young trio.

And according to royal expert Tom Quinn, there is a 'secret code' that Kate uses that keeps the kids in line.

He wrote in his book Gilded Youth, An Intimate History of Growing Up in the Royal Family: "When Prince Louis misbehaved at the late Queen's Platinum Jubilee for example, by sticking his tongue out at this mother, Kate's reaction was praised by a team of expert commentators.

"She apparently used a secret code to calm the children, as she does on occasions - she simply says 'let's take a break'. But as a former staffer explained, the children know these few words carry far more weight than we might imagine."

Prince Louis has been snapped behaving cheekily. Max Mumby/Indigo/Getty Images)

But the rules don't stop there for the family, and reportedly pertain to their home at Adelaide Cottage, a four-bedroom property in Windsor Home Park.

The house is steeped in history, having originally been built in 1831 for Queen Adelaide - and the Waleses moved there in 2022.

It seems when at home the royal family are not keen on raised voices, and apparently go to great pains to ensure the noise is kept to a low level.

A source previously told The Sun: "Shouting is absolutely 'off limits' for the children and any hint of shouting at each other is dealt with by removal.

"The naughty child is taken away from the scene of the row or disruption and talked to calmly by either Kate or William. Things are explained and consequences outlined and they never shout at them."