White worms are one of the better live foods for conditioning fish for spawning or to get the picky eaters to eat. They are about 3/4″ to 1″ in length, when feeding to fish you need to be careful to offer a varied diet. White worms are high in fat content. They will also survive under water for several days, but if you have gravel in your tank they will wiggle themselves into the gravel away from your fishes hungry mouth.
While the discussion of how to keep the worms varies from person to person, I keep mine in coconut fiber rather then a peat/soil mixture. But they also do quite well in African Violet soil. I soak the medium until it cant hold anymore water then I squeeze it as much as I can, then it will be slightly damp. Put about 1″ of the medium in the bottom of a plastic container. I like to use those plastic shoe boxes or sweater boxes, they are just right and the lid is loose enough to allow air in without having to make more holes to allow air in. After you have done this you can add your starter culture. Now the culture will like a lower temperature around 55 to 60 degrees. This can be done easily by getting an old cooler and storing your culture in that. Just get a two 2 liter soda bottles, and put water in them and freeze them. Then just alternate putting the frozen one in the cooler and the other in the freezer, I do this when its time to feed them. Now on feeding the worms, you can use old fish flake if you wish. I use baby cereal, oatmeal to be exact. I always use up all my flake for my fish and the cereal is not that expensive. Put just enough food in that the worms will eat it in one day, you don’t want it to go moldy. You will also want to fluff up the culture once a week or so, that way the medium doesn’t get too compact. You will want to add a little water once in awhile to keep the culture going, but don’t do too much, if the worms start crawling up the sides you know that its too moist.
You will want to start a new culture when you notice your worm population diminishing or the medium looks darker, you will notice the difference. Then all you need to do is start new medium and add some of your existing culture to it, don’t get rid of that one yet, wait till you know the new culture is taking off.
Now to harvest the worms can be a little tricky, I find that after feeding time they will all be clumped at the surface around the food, after all the food is gone I grab some of those worms and put them in water to rinse them off. I have heard of people putting a glass sheet and putting the food on top of that, I have not tried that because I have had good luck using my method.