Royal children speak together for the first time in video

Prince William and Kate Middleton have shared a rare video of their children, featuring a very familiar face.

The video, shared to the Duke and Duchess of Cambridge's official Instagram, shows Prince Louis, Princess Charlotte and Prince George asking veteran broadcaster and natural historian Sir David Attenborough questions about the environment.

It's believed to be the first time the children have spoken together on camera.

"We've got some questions for you, @DavidAttenborough," the post says.

In the video, Prince George asks Attenborough which animal he thinks will next become extinct.

"Well, let's hope there won't be any because there are lots of things we can do when animals are in danger of extinction," Attenborough replies.

Next is Princess Charlotte, who asks the 94-year-old if he likes spiders, followed by Prince Louis, who asks what Attenborough's favourite animal is - the answer being monkeys. 

At the time of writing, the video has been viewed nearly 3.5 million times on Instagram.