Worms come in two sizes as fishing bait. The most popular are large nightcrawlers and smaller garden worms. The promary use for these worms is fishing bait, so to be effective you must live near somewhere close to where you can fish, or go to where there are fishermen.
The basic equipment you will need is an empty tin can and a flashlight equipped with a red filter of some kind. Many users of this equipment use red cellophane as a filter. Many others don't use a filter at all. Nightcrawlers are not affected by red light, but they will head for cover if a white light shines on them.
The worms you are seeking are nightcrawlers that as the name inplies only come out at night, on a warm damp night is best. The best place to catch nightcrawlers is on a closely cut lawn. This might be at your own house, a city park or a golf course.
You have to be bent over to see the nightcrawlers in the grass, and be quick of hand to catch them. Once you have caught your work they are put into the tin can. Some professional worm catchers tie a tin can onto each of their ankles.
Nightcrawlers are usually kept in a refrigerator in a bed of peat humus, or shredded newspaper until they are sold. The average price for these worms is from $1.50 to $2.00 per dozen. Check around to see what the prevailing price is in your area.
The other worm that is commenly used as bait is the garden worm that is dug from the ground with a shovel. they are usually caught when you are spading a garden. A compost heap will attract these worms like a magnet by the millions making them very easy to catch. Like nightcrawlers these worms are kept the same way. Garden worms usually sell for $1.00 to $1.50 per dozen.
The worm business can lead to the creation of a full fledge sporting goods store specializing in sport fishing. In case you didn't know it sport fishing is the second largest sport in America.