Q: I include 'worms' as a subset of the larger category of 'bugs.' Others disagree. What's the proper classification scheme? Are Worms bugs?

A: Donovan points out that worms are "annelids", but that doesn't cover the question, I think, since the term "bug" is more a value judgment than a true category. "Germ" is another of those imprecise terms that is used frequently when we are young, but doesn't correspond well to true taxonomy. A "bug", as referred to by children (who use it most often), usually means "any creepy thing I can catch and scare little girls with". Worms fit very comfortably in that group, along with beetles, spiders, and roly-polies (aka "pill bugs" and "wood lice").

Therefore, if it:
1. is small
2. is alive
3. is squishy, or chitinous and many-legged (but not four-legged)
4. would make your sister scream if she found it on her arm or in her sandwich
5. is best left out of doors

...then I'd say it's a bug.