The humble lugworm, used as bait for generations, is a common sight on sand and mud. Or rather their distinctive casings are since the lugworm itself seldom leaves it’s burrow.
The burrow is a U-shaped tunnel that begins at a shallow depression, this is the head end of the lugworm from which the worm ingests sand. It processes it and forces the sand up the tail end of the burrow to form the distinctive castings on the surface.
The common lugworm species found on these shores (Arenicola marina) grow to a length of 130mm (5in).