Whiplike, the worms sped towards his hand. They were like snakes, at least eighteen inches long, as fat as his wrist and as swift as arrows. He staggered backwards as the first worm’s sharp teeth bit into his flesh. It didn’t let go…

As he struggled to reach the dinghy, he felt a searing pain on his bare foot, like a red-hot whiplash, rendering his leg useless. It felt like nettle stings, but a hundred times worse. Floundering in the water, he spluttered in agony as the poison shot into him. When he finally resurfaced, he saw them - more jellyfish were approaching, drifting towards him…

The caterpillar was huge, green and hairy – the biggest the boy had seen – and it wasn’t alone. The insect stowaways had attached themselves to his clothing. As he picked one up for closer inspection, a pain like hot needles shot through his arm. Then he felt the other wriggling across his front, where it began to penetrate the soft flesh of his stomach, burrowing into his skin…