Crouched over a thermal pool, I can see dozens of warm water creatures the size of apple seeds quietly living their best lives on floating mats made up of bacteria, algae, woody debris and leaves. The sulphur-rich water smells like rotten eggs and wants to be turquoise but it’s dominated by globs of green, brown and white scum. You probably wouldn’t notice the tiny brown aquatic snails unless someone told you what to look for.