Tardigrades are also known as water bears, but the actual word means ‘slow paced’.

At only about 0.5mm long, they can survive exposure to -272.15°C, while others can withstand temperatures of up to 150°C.

If a tardigrade is dehydrated and loses up to 99% of its water content, its living processes can be near-suspended for several years before being brought back to life. In its dehydrated state, it is known as a ‘tun’. A tun’s metabolism lowers to as little as 0.01% of its original rate.