After an hour of this nature romp, you may feel that you, too, have mosquito bites, heat rash and spiders in your hair. It's vivid escapism, in the same format as last year's Expedition Borneo: biologists and film-makers hack around the jungle. But this time we're in "the largest unspoilt rainforest left on the planet" - the apparently pristine wilderness of Guyana. I say apparently because that's what the team are there to establish, and the more rare species that they can locate, the better the case for keeping the loggers out. But in TV terms, the result lets you imagine, as far as you can from a cushy sofa, the sounds, smells and itches of the jungle. The star of the show is insect expert Dr George McGavin, who takes on a colony of army ants and ends up fleeing in pain while muttering a goodnatured "Entomologist nil - army ants one!" He also finds wonderfully weird whip-spiders that look like sci-fi props, while Steve Backshall abseils down the 240m-high Kaieteur Falls and finds gorgeous crabs and frogs at its base. Magic.