I know what you're thinking...

Why on earth has murmuration uploaded this pile of nonsense (twigs).
Well, this is a caddisfly larvae in his wee hoose, or suit of armour, and if you look closely you can see him poking his wee head out (largely because he's angry because I picked him up out of the water to have a closer look!) Callum and I found lots of them in a pond at Pitmedden forest which was full of mating frogs. We wouldn't have given them a second look if they hadn't been moving about and we were a bit spooked by all the moving twigs and stones!
In doing a bit of research I found this page. Scroll down to the bottom to find some amazing jewel encrusted caddisfly larvae! 
http://seawayblog.blogspot.co.uk/2008/12/amazing-caddisflies-and-curious-story.html