You're stuck in one of the hottest, driest places on Earth, parched. There are no streams or lakes, and little rain. How do you hydrate? If you are a Namib desert beetle you drink the occasional fog.
The beetle lives in the Namib Desert, a bone-dry expanse of sand on the south-west tip of Africa that gets about 1cm of rain a year. But the beetle has a clever way to quench its thirst: its body harvests water from the air.
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It's a refreshingly simple design. The beetle's shell-like armour is covered in tiny bumps with water-attracting tips. However, the slopes and troughs between the peaks are made of a super-repellent microstructure coated with a slick, waxy substance. Thus, as wet fog blows by, the 'sticky' tops of the protrusions snag minute water droplets, which grow and eventually roll down the beetle's back, into its mouth. It's like having a permanent hydration pack that refills itself.
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Even with this amazing piece of evolutionary engineering, the insect rarely has a drink, as morning fog forms only once or twice a week. Every drop counts.
To this end, the beetle faces into the wind, raises its rear and lowers its head to incline its body at a 45° angle to the ground.
This maximises the harvest (and efficiency thereof) and also ensures that the water ends up in the right place.
Scientists are looking to copy the design for a host of uses, from rain-collecting tent covers and roof tiles to better air-conditioning systems.