Recently a neighbour noticed her lawn covered in worms when she let her dogs out for their final comfort break. We remembered a village event held on the playing fields, when people dancing in the rain caused worms to emerge. You may also have seen gulls ‘paddling’ their feet to lure worms to the surface. Rain can attract worms up for breeding. Other vibrations stimulate the movement of moles, causing worms to emerge to escape them.
In the southern USA, worms are collected for bait by worm grunting*. A stake driven into the ground has its top rubbed with a ridged metal bar. Worms, attracted to the surface, are collected. Look on YouTube for ‘Worm Grunting in the Apalachicola National Forest’.
* Also called ‘charming’ or ‘fiddling’, Ed.