Ananova:

A book teaching kids how to make paper aeroplanes, climb trees and play conkers has become a surprise best-seller.

The Dangerous Book for Boys has shot to number five in Amazon.co.uk's Hot 100 charts since it was published last month.

And sales have leapt by 700% in the last week. The book is by ex-English teacher Conn Iggulden and his theatre director brother Hal.

It explains how to build a treehouse, fish, skim stones and make a catapult. There are also chapters on insects, pirates, coin tricks, marbles and dinosaurs.

Conn said: "We wrote it to be a compendium of all the things we wanted to try and to know when we were very young. It's the attitude that we wanted to recapture - when everything was interesting and danger was fun.

"You can't stop boys being curious so they might as well have the tools and instructions to focus that curiosity."

The book also includes stories of courage from historical heroes including Scott of the Antarctic, Robert the Bruce, Lord Nelson and Douglas Bader.

Conn added: "Their example is more important than ever. Not one of them would have understood the health and safety culture. If they had, Scott would have stayed at home and Douglas Bader might have kept his legs and lost the Battle of Britain."