Cue sinister music: here’s the animal with the most formidable jaws currently living in my water butt. Strictly speaking it’s an omnivore, dining on algae as well as other animal life, but it has impressive chewing equipment. It’s the larval stage of a chironomid midge – one of those little midges that form dancing swarms at dusk – and it’s the third commonest organism in the water butt at the moment, after the euglenoids and Vorticella (see previous posts). It’s about a millimetre long. The adults do not bite and are unable to feed, so have very short lives - just long enough to mate and lay a gelatinous string of eggs on the surface of still water.