HEADLINES:

The £78 million extension to the Natural History Museum opens next week with a unique chance to see some of the world's top scientists at work.

The Darwin Centre is the largest development in the museum's 128-year history and has at its heart the 65-metre, eight-storey Cocoon structure housing 20 million exhibits, including huge tarantulas and metre-high poisonous plants.

It includes a laboratory where visitors will be able to watch some of the 220 scientists based there and ask them questions via an intercom.

Museum director Dr Michael Dixon said of the extension: “It shows what goes on behind the scenes and shows it is socially relevant. It is not just a museum, it is a major research institute,” he said.

The Cocoon's team includes Max Barclay, a beetle expert who looks after the museum's 10 million bugs; Jan Beccaloni, curator of arachnids; botanist Alex Monro, who leads expeditions into virgin rainforest; and Blanca Huertas Hernandez, in charge of the centre's 3.5 million butterflies.

They are carrying out some of the museum's most important work on mosquito DNA barcoding, helping in the fight against malaria.

Several projects deal with evolution, looking at changes in behaviour and the ecological background to primate evolution.

Sir David Attenborough will join Prince William at the official opening next Tuesday.