Ruth Binney, Amazing & Extraordinary Facts, The English Countryside, Blue Ash, llinois, David & Charles, 2011, p. 119
A twig that walks-not a figment of the imagination but the mobile home of maturing caddisflies. The adult female lays her eggs in or near water which, when they hatch, develop into « architectural » larvae.
Using pieces of sedge, twigs or stones as building materials they bind these together with silk spun from their bodies, often chewing vegetation to make it more malleable and decorating their homes with pieces of shell.
When a larva gets too large for its case, it first moults, then builds another larger case to grow into. Only when fully grown does the larva attach its case to a reed or stones in the water. It then seals itself within until the fully developed pupa emerges as an adult.
The caddisfly is named for the caddisman, a pedlar who roamed the countryside. He was often a cloth salesman who advertised his wares by wearing strips of brightly coloured fabric or yarn. The name may also link to the caddy or box traditionally used for storing tea.