Have you noticed much activity from the worms? If it is warm enough they are probably coming up at night to eat and look for a mate. You would have to lay the tarp in a place where they already visit that has dead vegetation for them to eat. I tried rubbing the stick against a stick buried in the ground, that never worked. I tried a few other things, which never worked. I found the only way to catch them was to go out in the evening with a bucket and a flashlight and pick them up off the ground. If you don't stomp around and move quickly you can snatch them up pretty easily. I only wanted a few for fishing, but ended up with a coffee can full of them in only an hour or so. The light from the flashlight would spook them if shined directly on them. The were the thickest around areas where leaves and debris built up. If the ground was too dry (here in NM) they were as thick, after a day of watering the yard, they were everywhere. Anyway, I would catch a can load, use a few for fishing and take the rest down to the barn and watch the chickens chase each other for worm pieces. They loved it!!