Where did you get your worm casings? I’ve made one site for night crawlers. I haven’t dug around to see if they’ve take up residence, yet.
I'm about to learn how my worm population fares. Last Spring the soil was loaded with healthy looking worms. In the Fall when I hand turned the ground there were not so many -- that I could see, anyway. The product description says the castings "may" include worm eggs. Hope so!