From what I understand, they eat what is/has decomposed on the food, not the food itself.

There is a lot of conflicting info out there, worms do eat a lot of the microbes that grow on the food, but they also eat the foods too, the big thing is that the worms need the food to decompose enough by bacteria that they can suck it up. The worms mouth is like a little straw, so they can't really bite off chunks of the food. Some foods like corn flour they eat so fast that it is impossible that the worms don't eat it direct.

As far as how much to feed, half the weight a day is a big claim, i'm in the weight per week camp. There is no real hard amount you need to feed worms, read the bin and feedwhat it will take

The worms cannot eat the food as is, it has to be broken down first, therefore the better the food can be chopped up , or run thru a juicer/food chopper the quicker the bacteria can break it down so the worms can eat it. There are times that I can look in the bin and see the bacteria at work, per "teeming with microbes".

As I understand it, worms will eat nearly anything organic that they can eat (exceptions mainly involving fatty things and animal proteins), but because they have tiny mouths and no teeth, their options are quite limited. They end up eating bacteria and fungal spores mainly, but as the other decomposers in the bin (both the microscopic and the macroscopic) break the food up into softer fare, the worms can and will slurp up the resulting slurry. This is why worms take better to food that's been frozen solid and then thawed: the formation of ice crystals bursts the cell walls, breaking up and softening the food so that it's easier for the worms to eat.

There are surely organisms that are passing through the worms' digestive tracts alive, and quite likely some that prefer to live out their whole lives inside the worms' bodies. Worm casts will definitely contain thriving populations of microorganisms. This is, as I understand it, one reason worm casts are so beneficial for plants. Microbial action is involved in nitrogen fixing, turning dead roots and shed leaves back into plant food, and some microbes are your best soldiers in the fight against other, potentially harmful, microbes. It's hard for a pathogen to gain a foothold when the area is already thoroughly colonized by other living things, things that can out-compete it and may even directly kill it.

Worms will eat whatever is soft enough for them to eat. They also eat microorganisms. They also contain microorganisms in their guts to help with digestion. The idea that worms never eat the food and only eat the microorganisms from decomposing food is, I suspect, an urban myth. Because if I put down food that the worms really like, they will attack it and eat it pretty quickly. It will show signs of worm consumption way before there has been time for microorganisms to break it down.

As for amount to feed, it really is dependent on lots of things: temp, texture/consistency of food, bin conditions, density of worm population relative to bin size, which food you're feeding (some food is beloved and will be gobbled up, other food is stuff the worms may feel "meh" about and it may linger for a while), etc. It takes some experience to get a feel for how quickly a given food will disappear in given conditions. Just learn as you go at first. As long as you have plenty of bedding, underfeeding is better than overfeeding in the beginning, so start with smaller amounts, monitor to see how quickly it's being eaten, etc. You'll eventually get a feel for it.

Agreed. But I think that too many people seem to think they have to go through weird fermentation rituals with the food which are just not necessary and could possibly lead to degrading the environment in a worm bin that is happily balanced. It's one thing if you have a huge outdoor worm enclosure or something or are breeding worms to sell, but for the person with an indoor bins or two primarily for the purpose of putting kitchen scraps to good use, it probably does more harm than good. I think getting the food into small pieces, whether by chopping or running through a processor, is really the only extra work that enhances results in a way that make a difference to the small-time worm bin owner, and the only necessary step for me, personally, is heating any fruit fly or gnat susceptible food enough to know I've killed any eggs or larvae (I usually just use the microwave). This strategy has resulted in a thriving worm bin and no gnats or fruit flies. I only freeze incidentally, when I have a collection of scraps I know the worms will like but they're not ready to be fed yet, in which case, instead of letting it ferment somewhere it can cause inconvenient odors for me, I chuck it in a bag in the freezer until they're ready for it.

We probably all have different philosophies, and people who want to or need to make things more complicated are, of course, not wrong or anything, but I think it's important for people starting out to know that just throwing food into the bins is fine. Sometimes, those of us, myself included, who aren't doing this as a personal passion or profit-making scheme but just as a way to be more environmentally conscious and get some nice compost for the garden as a side benefit, can end up thinking this requires more work and complication than it does.

Thanks for everyone's inputs. Not really asking for advice but for clarity as to what's actually happening to the food scraps in a worm system.

You asked if they ingest the food itself or just feed on the organisms. I think it is clear they physically ingest almost anything soft enough. What they digest - absorb for nutrients - is what is broken down enough for them to absorb. Those microbes do a lot of the work but I don't think you could say they aren't digesting some 'food' directly, just that they are reliant on the microbes to make it all work. But that's true for cows, for us, and probably all animals. They also seem to have their own gut 'ecosystem' of microbes, which is (I believe) why the vermicastings are so rich in life - they help the worms digest but also ensure the environment around them keeps the process going. Just my thoughts of course, not an expert.

Composting worms can eat up to their body weight per day in ideal conditions. Odds are the conditions in our bins are not ideal, so we shoot for less than that. What they eat includes their bedding, so if you feed their body weight of food every day, you are overfeeding them.

Worms ingest anything that is soft enough for them to slurp into their mouths, and is covered in microbes. They derive their nutrition from the microbes they ingest. How exactly that is done is not known.