Today’s fashion for self-built homes may have started a few decades ago, but for nearly 200 million years, a family of insects have been quietly developing their own, des res. Depending on where you come from, they are sometimes known as ‘straw worms’, or ‘case worms’, but for most they are simply called ‘caddis’. The origin of the word "caddis" is unclear, but it seems to date back as far as Izaak Walton's 1653 book The Complete Angler, where the angling hero notes how to fish for roach or dace using "case-worms or cadis" as bait. There are almost 200 species of caddisfly in the UK, the largest of which is more than 3cm long. In this episode of Living World, Lionel Kelleway hopes to find just a few of this number when he is joined on Lake Windermere by caddisfly expert Ian Wallace, who attempts to guide Lionel through these curious pond, lake and river dwelling insects. Along the way they discover some of the intricate biology which leads to the creation of their self built homes, a process that has even been adopted by jewelry designers in recent years. Lindsey Chapman hosts this revised Living World from 2007 and gently brings the story up to date for today's audience.