It came as no surprise to the Edinburgh International Book Festival audience to learn that Simon Chapman, author of the Explorers Wanted books, had been stopped and questioned by officers at Heathrow airport. After all, not many people travel from London to Edinburgh with what he had in his rucksack.

As he brandished his machete, unsheathed from its leather pouch for everyone to see, gasps of awe came from all of the primary children, not to mention the accompanying teachers and parents, in the audience. As he swiped it through the air to show how he cuts down vines in the jungle to clear his path, all eyes followed the curve of the blade.

For an hour, Chapman brought a bit of the jungle to Edinburgh, even setting up camp to show how to hang a hammock. Images of his travels were projected on to a screen at the front of the tent and he convincingly imitated monkey sounds, making one or two children jump out of their seats.

He asked the children what essential items they thought he should take to the jungle and revealed the contents of his rucksack. Volunteers in the audience dressed up like explorers; one boy who went up to try on a green rain cape, mosquito net and head torch, happily sat in the attire for the rest of the session.

Chapman, who is a physics teacher at a secondary school in Lancashire, was enthusiastic, energetic and engaging, knowing what would make the audience gasp in shock or delight. As he told tales of holding a crocodile by its tail and being stared at by a puma close by, all were captivated.

Often described as a “real life Indiana Jones”, Chapman has been making trips to jungles all over the world, from Borneo to the Amazon, for 15 years, but only in 2001 began writing books about his travels. He explained why to his audience.

“My pupils asked me lots of questions and I thought it would be easier to write them all down,” he said. It was not hard to believe when you saw the number of fingers jabbing the air during his question and answer session.

The children were eager to find out more about his travels and the animals he has encountered.

Animals, it seemed, were the theme of the day. Before Chapman’s session, Nicola Davies, a zoologist and former television presenter of The Really Wild Show, had been in the same tent entertaining primary children with tales of bats, whales and dolphins. She had them communicating in a whale language and performing a whale song, and was not short of volunteers to come forward and be transformed into bats, whales and dolphins.

She told all kinds of disgusting facts about vampire bats, such as how they urinate as they suck blood and will kindly regurgitate some of their food for a fellow bat to consume. Then she declared: “Bats produce a very special kind of poo.” It was, she said, like strawberry jam.

It wasn’t surprising that she went on to talk about whale poo, since her latest book is entitled Poo: A Natural History of the Unmentionable. There were lots of laughs and “Urgh“s as she told how she got covered in whale poo, which was pink from them eating so many shrimps, and how it ended up in her curry, “but it was OK because it was a fish curry”.

Both Chapman and Davies brought their books to life, captivating their audiences and inspiring them to find out more. But it was a different story for American author Jennifer Donnelly. Her audience of secondary pupils was less easy to engage.

Donnelly’s novel A Gathering Light, won the Carnegie Medal and is in the top 10 lists in bookshops, being bought by teenagers and adults alike. It is her first novel for young people and has been described as “one of the finest debuts of 2003”. It weaves fiction with historical fact about a 1906 murder in New York state and makes for a compelling story. But her audience, who listened intently to her reading excerpts and talking about the process involved in writing it, were reluctant to ask questions.

Donnelly explained that a novel needs drama, tension and some kind of conflict and to write one you need inspiration. “Family stories are a great source of inspiration,” she said, explaining how she had been helped by stories her grandmother had told her.

The amount of research she undertook for the novel was phenomenal, not only looking at newspaper cuttings and old photographs, but also delving into details such as how much milk a cow would have given 100 years ago, the types of chicken feed farmers would have used then and different farming techniques.

Despite the mass of information divulged, very few hands went up during the question and answer session. Most belonged to teachers in the audience, who had obviously enjoyed the book.

At another event for secondary pupils, reactions were very different.

Pupils and teachers were keen to question Malorie Blackman. In fact, there were so many questions that she did not get to read as many extracts as she wanted from her novel Noughts and Crosses.

As pupils gathered to see the best-selling author, there was an air of excitement as they waited for her to walk on stage. From the moment she started speaking, they were hooked.

Blackman has written more than 50 books for children and young adults and has a string of awards to her name. It was evident from the questions session that her books had been well read; her audience wanted to know about the future of her characters.

Bubbly, passionate, and friendly, Blackman surely inspired some of them to put pen to paper. The event was enlightening and provided plenty to talk about back in class, including the words of advice that were once given to her.

On one writing course she attended, the members of the class were asked each week to read out something they had written. “I hated this bit,” she admitted. “The teacher asked if I wanted to read something and I’d say ‘No thank you’. After about four weeks she said to me: ‘Malorie, you are going to have to shit or get off the pot.’

“It was a good piece of advice,” said Blackman. “If you want something, go for it.”