"Yeah, cool!" they replied, immune to the dangers of being stranded deep in the Belizean rainforest - close to venomous arachnids, far from any anti-venom. While the boys looked up at Ramon with glee, mum and dad were a little less sure. If the boys saw a tarantula it would not be of the zoo variety (as in safely behind glass) but the real McCoy.
Ramon led the boys further along the jungle path, stooping to peer at the ground before stopping abruptly. "Here, look," he said. We all squinted, peering into a hole whose tin-can circumference was covered with a fine, wispy web.
With a small twig, Ramon probed gently at the burrow and we all leapt back as, at the entrance of its domain, appeared a large, hairy spider. Ramon assured us that while this particular species was not deadly - which was comforting, given that Belize is home to spiders so large they eat birds -you wouldn't want want to take one home in a matchbox.
The boys were ecstatic, and over the next few hours became worryingly adept at discovering tarantula burrows and coaxing their occupants to bask briefly in the shafts of jungle sunlight. They were similarly unafraid of the snakes that would occasionally flash across our path; as Ramon led us deeper into the Caracol reservation in western Belize, we soon realised it was a good idea to watch where we were treading.
Vast trees towered above, their branches rustled by howler monkeys that we could certainly hear but rarely see. On a rainforest safari, seen but not heard is a rule you need to learn early to avoid disappointment. Belize is home to some of the rarest species on earth, and your chances of seeing them are equally slim. Baird's tapir, for instance, a Hoover-nosed bovine known as the mountain cow, is an excellent swimmer, and spends most if its time submerged in the rivers and waterholes that litter the forest.
We were on our way to the ruins of the Mayan city of Caracol, but for all my own sense of anticipation, I doubted stone ruins would match the thrill of being in virgin jungle. Needless to say, I was wrong; Caracol is nothing short of astonishing. This almost immaculately preserved city rising in the midst of the jungle was, in its heyday (between AD650 and 700), occupied by 150,000 people, only 50,000 fewer than occupy Belize today. The country occupies some 35 square miles, and archaeologists are still discovering new sites.
Caracol gave Harry and Elliot what young boys seem to prize above all else - something to climb. As the adults laboured in the heat up the vast steps of the 140ft high Sky Palace, Harry and Elliot raced to the top. From here, the view across the jungle canopy was breathtaking. Green stretched as far as the eye could see, a vista which included neighbouring Guatemala just four miles away. Flocks of macaws chattered busily among themselves and, unsurprisingly, the rare jabiru stork was nowhere to be seen.
Ramon explained that we were standing on the spot reserved for Mayan kings, whose status seemed to have been predicated on their size; the average Mayan was just over 5ft, but the country's rulers were a lofty 6ft or more; hence the large stone steps. Cut a foot-and-a-half high to deter the peasants who lived below, they were easy work for the kings, whose living quarters occupied the upper reaches of the temples.
The Mayans believed in reincarnation, and ritually sacrificed their most beautiful women, prized warriors, even children, because, as Ramon said, "it was seen as an honour to be chosen to be sacrificed". To ease the passage into the next life for those selected, victims were often drugged before being executed.
We reflected on the gorier aspects of Mayan life in our casita, a tall, wooden house with a thatched roof and slatted floors covered with hand-woven rugs of Mayan design. It was situated at Blancaneaux Lodge, in the Mountain Pine Ridge Reserve. Blancaneaux is owned by the American film director Francis Ford Coppola, who discovered the area 20 years ago when searching for a jungle retreat similar to the Philippines location he had used in making Apocalypse Now. Coppola originally used Blancaneaux as a private writing retreat, but subsequent casitas have been added, built on stilts next to a gently flowing river and surrounded by dense jungle.
The walls of our casita were adorned with jaguar masks; these big cats, native to the rainforest, are fearsome predators. Lower down the food chain, other mammals typify Belize's idiosyncratic fauna. The kinkajou, for example, a possum-like, fruit-eating mammal with a long, prehensile tail, is known as "The Nightwalker".
Of more interest to our own species were the design features of our casita: bathroom open to the sky and hammocks in which to lie and listen to the sounds of the jungle night. The volume produced by the bullfrogs was tremendous, almost as startling as the view overhead: the sky was littered with stars, and to the east, out towards a Caribbean sea obscured by miles of rainforest, lightning lit up the night. While it is hard to look on Blancaneaux as anything other than paradise found, it becomes largely academic when travelling with children unless the offspring are welcome. Fortunately, Coppola's very Italian sense of family, shines through his creation; for all the "exclusive" and "luxury" tags one might attach to Blancaneaux, children are not merely tolerated, but positively welcomed.
The staff, from guides such as Ramon to the waiters and waitresses, went out of their way to talk to the boys, showing them the many wonders of the jungle a stay at Blancaneaux can offer. These include horseback and flower tours, hikes along easy jungle paths and outings to numerous caves and creeks. Not forgetting, of course, the cornucopia of lizard, snake, mammal and insect life.
Coppola has three lodges in central America: two in Belize (apart from Blancaneaux, he has another in the coastal resort of Turtle Inn) and a third across the border in Guatemala. La Lancha lies on Lake Peten Itza in the east of Guatemala, and this was where we headed as we continued our odyssey with a three-hour drive, marvelling at the names of towns thrown up by Belize's English-speaking colonial past. There really are places called Lucky Strike, Young Girl, Baking Pot and Never Delay. There is even somewhere called Go To Hell.
Perhaps Go To Hell is a lovely town, full of joie de vivre and at ease with itself, but should its inhabitants ever feel in need of relief from their domicile's less than welcoming moniker, La Lancha is just the job. Here, brightly painted casitas overlook a tranquil lake and iridescent humming birds dart from leaf to leaf. There is a swimming pool and a restaurant, and only the extraordinary early-morning racket of the resident howler monkeys interrupts the sense of peace.
La Lancha is an excellent base from which to explore Guate-mala's own jungle highlights, not least the wonderful ruins at Tikal, the largest Mayan site yet to be discovered. Like Caracol, Tikal's power to mesmerise comes as much from its location as the steep-sided temples that rise above everything else in the area. Tikal emerges from the depths of the jungle, and while the vast site now has a series of paths and cleared plazas (and, unlike Caracol, possesses shops and a restaurant), the sense of a live - and dangerous - rainforest is constant. Spider monkeys surge through the trees, a crocodile lurks in a pool at the entrance. Keel-billed toucans perch imperiously, and snakes slink between stones and logs.
It is humbling to think that here the Mayan race built a complex civilisation and developed mathematics, astronomy and hieroglyphics as well as irrigation systems and trade centres.
"The Mayan people were the most advanced in the world," said Jose, our guide at Tikal. We were pondering this back at La Lancha, idling in the hammocks, when we heard a shout from the boys. "Guess what. There's a tarantula hole behind our casita!"
I rushed round to see them trying to persuade a reluctant spider to say hello. Not, without an expert guide, the most sensible of undertakings. But I would wager that Harry and Elliot learnt more in our five days in Belize and Guatemala than in a term at school. And luckily, the tarantula didn't bite.
Step this way for a walk in the wild side
Alex Wade and his family travelled to Belize and Guatemala with Steppes Travel (www.steppestravel.co.uk, 01285 880 980). Tours of the area start from £2,235 per person, including return flights from the UK, internal flights and transfers. In Belize the Wades stayed at Blancaneaux Lodge (www.blancaneauxlodge.com), which is owned by the film director Francis Ford Coppola. Recommended activities include visiting the Mayan ruins at Caracol, Barton Creek cave and the ruins at Xunantanich. Horseback and flower tours are also available, as are maps listing easy hikes in the area. Look out for the fan in the bar at Blancaneaux - it was used in the opening sequence of Apocalypse Now. In Guatemala, the Wades stayed at La Lancha, also owned by Coppola. For details, visit www.blancaneauxlodge.com then click on "La Lancha". Activities considered a must include a visit to the ruins of Tikal, the island town of Flores, Lake Peten Itza and the Cerro Cahui national reserve, as well as jungle canopy and bird-watching tours, and the jungle zip-wire just outside Tikal national park.