Unlike certain other "make-your-own-home" invertebrates — trapdoor spiders, hermit crabs, bivalves, etc. — caddisflies are neither hideous nor mundane. They're pretty cool.
Most creatures that create shells using harvested materials aren't exactly "skilled laborers." Though their shells are functional, they're very crude-looking to human eyes. Creatures that generate their own shells, such as snails, generally make nicer-looking homes for themselves. To my eye, caddisflies combine the methods and source materials of the former group with the technical skill of the latter group. Take a look at this...
|The case of a brachycentrid caddisfly|
That is a caddisfly case constructed from leaves, grasses, and other soft plant matter. Its sides are perfectly flat, and its opening is a perfect square (Source). Even though it's a little silly to apply a human sense of the aesthetic to the evolved behavior of an insect, that's still remarkable — even among caddisflies. Most cases look like a hodgepodge of random materials, but this looks like a proper structure!
Even more remarkable is that certain caddisflies are known to repair their cases when damage is incurred. My knowledge of these creatures is still very limited, but I'm already making a bit of an informal study of them (when my formal studies don't subtract from my time). Hopefully I was able to supplement the class's knowledge, just a little bit.
If not, I'm not all that concerned. I'd still be interested, regardless.