I think different people find different results with their worms. Aside from the obvious...salt, chemicals, things of that line, I'd say pretty much anything goes.

Some people don't feed their guys onions, (mine like them), citrus ....mine eat lemons and grapefruits. I feed mine rhubarb, and I wasn't sure because of the tartness, bitterness, but when the food breaks down, it's all the same, in my opinion. Even hot peppers are edible.

Having said that, things in moderation is the key. Early on I fed some cooked rice mixed in with their food. The rice overheated, clumped and cooked most of my herd. I've never fed them rice since.

When you're trying something new, just put a tiny amount mixed in with their regular goodies and see how they like it.

Fire.

Birds.

Ham-fisted toddlers.

But no, nothing is strictly off-limits as long as it is actually some kind of food or vegetation. Just keep in mind that anything animal-based is going to take a lot longer to break down into worm food and is going to stink pretty good in the meantime.

That's why there's the no meat and dairy rule - it stinks and takes longer to break down.

Even meat and dairy can be eaten by worms if the right steps are taken before hand. I know Bokashi and BSFL can render meat and dairy into feedstock for worms

So - if BSFL are present in the worm bin can meat or dairy go directly in the bin?
BettyN

I have always added meat scraps and dairy to my bin, with no problems. I don't take any steps beforehand, and I don't have black soldier flies.
You have to bury it or you will smell it, but even that is not a huge problem, unless you have the bin right in your living space. (My bin is in my basement.) I put some fish scraps in recently and I could smell it if I lifted the lid. So I didn't lift the lid. The smell subsided in a day or two.
Occasionally my cats bring me a dead mouse. I put it right in the bin. It soon disappears.
I don't even think the meat and dairy takes any longer to be consumed by the worms than anything else. Certainly no longer than corn cobs, even if they are chopped up!
mbetts

I have an outdoor worm bed and it is inhabited by their archenemies, the voles. But still they survive and thrive. And they are often visited by robins. But still they survive and thrive. The top six inches of the bedding freezes solid in the winter. You guessed it - by spring there are loads of worms.

They are very resilient creatures.

Here is a link that might be useful: The Amazing Race recaps - funnies to read while your worms are eating

Too much love, feeding, checking, ATTENTION!

Anything salty,and vinegary-like. Bad, bad bad