Formal is not the word your looking for. Literal. People interpret the words literally. The can't/ don't understand figurative language like sarcasm, symbolism and metaphor.

Cellar spiders/ daddy long legs have become catch-all terms for any spider or pseudo spider with tiny body and long legs. Anyway, webs get disturbed all the time in nature. The spider just rebuilds. As long as you don's bump in to them, they will just repair the web. If the web needs repair too often, then the spider will move elsewhere.