The Duchess of Cambridge is to become a volunteer in the Scout Association, working with youngsters near her home in north Wales.
The Scout Association said she will be teaching boys - aged from six to 10 - a variety of skills including putting up tents and lighting fires.
She will work with youngsters near her home on Anglesey, but will also assist in other areas of the UK.
The duchess, a former Brownie, has also become patron of four charities.
Across the UK, she has accepted honorary positions with Action on Addiction, East Anglia's Children's Hospices, the Art Room and the National Portrait Gallery.
The Scout Association said her role with them would be as an active volunteer.
A spokesman said: "She doesn't want to turn up and open things, she wants to volunteer, and that's the difference.
"It's about rolling up your sleeves, getting your hands dirty, and that's what she'll find is fun."
Her work will start with groups in north Wales, where her husband William works as an RAF helicopter pilot, but could see her helping across the UK, or wherever she lives in the future.
The spokesman added: "She will be doing all the things that any other volunteer leader would do.
"She might be teaching them how to put up a tent, light a fire, read a map and compass - anything that any other leader would do on a regular basis."
Adventurer, TV presenter and UK chief scout Bear Grylls said: "The duchess has an incredibly busy life, which makes it all the more inspiring that she has chosen to volunteer alongside us."
He added: "I think what's lovely is that she's going to feel exactly the way that lots of young scouts feel when they first join, which is a little bit nervous...that's what scouting's about.
"You are part of a big family."
When Grylls was appointed as the youngest ever chief scout at the age of 35 in 2009, interest in volunteering for scouting immediately increased fourfold.
A former SAS soldier, Grylls climbed Everest aged 23 in 1998, two years after breaking his back parachuting.
He has since carved a television career as an adventurer, and has written several books.
He added: "I'm really exited just to open her eyes to some of what scouts are up to, and the more you see, the more amazing it is."
John Muston, of the Scout Association in Snowdonia and Anglesey, said: "It's great that the duchess can find time in her busy schedule to help scouting.
"The demands and pressures of modern life often mean it's harder for people to find time to volunteer, so for some time now the scouts have offered volunteer roles in such a way that adults can get involved flexibly, similar to the way that the duchess is supporting scouting."
It has been announced that Kate has become patron of four charities.
St James's Palace said the choices reflected her interests in the arts, promotion of outdoor activity and supporting people in need of all ages, adding that the organisations "compliment the charitable work already undertaken by her husband".
The duchess is already patron of the charitable foundation her husband founded with his brother Prince Harry, but these are her first external patronages.
The Art Room uses art therapy to help children with issues like low self esteem and Asperger's syndrome.
Action on Addiction, helps people with a range of addictions at treatment centres across England.
East Anglia's Children's Hospices (Each) provides care and support to children with life-threatening conditions and their families across Cambridgeshire, Essex, Norfolk and Suffolk.
The duchess has also accepted a role with London's National Portrait Gallery.