Most likely you are looking at pot worms. White, maybe an inch long at most and are TINY. These are generally caused by over acidic conditions, which is caused by over feeding or excess moisture. Most likely over feeding caused the excess moisture, which make for perfect acidic conditions for these little pot worms.

VERY common, no need to panic, they don't hurt anything but they indicate conditions that are less then ideal for your worms. Just back off the food for a week or two, add more bedding and let everything dry up a bit. Note how wet everything is now and try to stay drier then your current conditions. Squeeze a handful of the material, if ANY water drips out when you squeeze things are too wet. Everything should be damp enough to hold together when squeezed but NOT drip. Hence, the "damp as a wrung out sponge", with the emphasis on "wrung out" or "done dripping".

Kat

also, putting bread in the bin encourages pot worms. I noticed this in my own worm bin (these days I compost the bread instead) and kelly slocum confirmed a connection between bread and pot worms (It was a long time ago though so I can't quote what she said about it) but it certainly led to outbreaks of them when I used to put it in for the worms

you may also be seeing some form of fungal activity, especially actinomycetes [a fungal-like bacteria], which could be an indicator that area of the bin has gotten hotter than desireable

Bill