I should have been more clear. The whole “rain sounds like X” theories come up all the time to explain why worms leave supposed safety in the ground to drown in puddles or get eaten by birds on the surface. I in no way meant to defend what I see as a ludicrous explanation for some folks having dumped bait worms out of their tubs (with their substrate intact) in little piles with little substrate hats.
I think the whole “rain sounds like…” thoughts are a bit daft. Rain will drown you if you’re in a tunnel or porous substrate. Even if you run the chance of getting eaten on the surface or falling into a gutter or puddle and drowning, your chances are still better than the 100% chance you’d have of drowning if you’d stayed in the waterlogging ground.