Chameleons use futuristic nanotechnology more advanced than anything humans possess to carry out their extraordinary colour changes, scientists have learned.

The process involves the active tuning of a lattice of microscopic crystals in skin cells called iridophores.

Not only do the crystals allow the lizard to shift rapidly from efficient camouflage and spectacular mating displays, but they also protect it from overheating.

Like some other reptiles, chameleons display a wide range of colours produced not by pigments but ‘optical interference’ between different wavelengths of reflected light from tiny crystals.

The crystals are arranged in layers within the iridophores.

The animal changes its colours via the active tuning of a lattice of nanocrystals

In studies of the panther chameleon, from Madagascar, scientists found that the creature actively controls the way its iridophore crystals generate colour.

Physicist Jeremie Teyssier, from the University of Geneva in Switzerland, said: “We discovered that the animal changes its colours via the active tuning of a lattice of nanocrystals.

“When the chameleon is calm, the latter are organised into a dense network and reflect the blue wavelengths. In contrast, when excited, it loosens its lattice of nanocrystals, which allows the reflection of other colours, such as yellows or reds.”

The scientists also uncovered a second deeper layer of iridophores containing larger and less ordered crystals which reflect infrared light.

By reflecting back the sun’s heat energy, the cells prevented the chameleon getting too hot in the tropical sun.

The research is published in the journal Nature Communications.