Bristol worms are a good way of telling if your over feeding , they are like the fuel gauge of your tank
Now if it looks like your being invaded with worms your most likely over feeding,
your only wanting to see maybe a small handful and thats what you want if feeding correctly
bristol worms do sting yes it's very painful , never work in your tank with out gloves as you never know where one is hiding it only takes a second to get stung
are there good and bad bristol worms No , they are a good part of the CUC
now if a bristol worm grows over 3inch I consider them as pests I've seen them 3/4 ft long but they can get bigger and they can and will take over these need to be removed immediately using extreme caution doing so , using a coffee can to keep them contained is best always tape the lid closed to prevent accidental release in the trash
never take advantage of the worm (oh he is tiny !! size don't matter when it comes to getting stung they all can do serious damage)
I am scared for life because of a stupid worm never under estimate the worm
I can tell you story's about these guys as I learned first hand