http://www.wormfarmingrevealed.com/
Attracting worms using hay and goat manure is a sure way to guarantee possession of 3 types of worms such as the composting worms, deep burrowing worms, and lateral burrowing worms.
It's important to mention that your ground must already support these worms in order to attract all types but even attracting just the composting worm is very beneficial.