About redworms,
it is my understanding that they are non-native worms used in vermiculture (worm composting, which is a special form of composting usually done indoors). The most common species is Eisenia foetida, and is small, red and requires higher temperatures and organic content than is found in gardens (at least in BC). I think the problem with them is they tend to have high bacterial content, and possibly some toxins as well. They are sometimes sold as bait for fishing, but are MUCH smaller than the nightcrawlers often sold as bait. I was reading about vermicomposting a while ago because I was wondering if the worms could be a good food source for herps and was disappointed to find out this might not be such a good idea.