Having the sandy soil that I do the population of earth worms is sparse. I don't want them for fishing I wanted them in an my garden area for their natural composting ability's. So naturally I don't care to shock them out of the ground but is their population were to increase to several hundred per sq foot it would be fine with me.
What I have done is to save the coffee grounds and the filters,the vegetable table scraps peelings egg shells and so forth into 5 gallon buckets then after a period of time I spread these on the garden after all harvest is done cut down any remaining foliage then moisten the soil and cover with sheet metal for the winter. Where there I used to be able only to find one or possibly 2 earth worms I am now finding several. Hopefully there will be 1000s by spring if the ground does not get too cold. I'm noticing they also eat the coffee filters.