Around here there are two kinds of worms. Red worms(used for fishing) they are small and well red.
Nightcrawlers also used for fishing,but they are MUCH longer and fatter. Red worms to me are probably baby nightcrawlers.
There are ways to grow them. I tried a few years ago and failed, but do a search on Google. LOTS of ways to grow your own worms.
Meal worms are another source of good eating, and IMHO MUCH easier and cleaner to raise than the red worms / nightcrawlers. Again do a search on them. Lots of info there. I remember my dad raising Meal worms. He just kept them in a Charles Chips tin can. *(I'm dating myself here) LOL Every so often when mom made mashed potatoes I would take the skins to feed the worms.