The Mystery of the Earthworm

We have had so much wet weather lately. We had almost 400mm in February and here we are on day 4 of March and we've had over 150mm. Everything is sodden and slippery. Anyway, I was feeding the girls this afternoon and happened to notice the pale pinky grey form of a dead earth worm - a good sized earthworm in their water container. Then, while I was giving the boys their afternoon treat of molasses and pollard I happened to notice the drowned bodies of another dozen or so worms on the bottom of their big poly water container. A glance in the cement tubs that we also use for water for the boys revealed yet more drowned worms of various sizes.  What the?
Thinking it through of course, what happens is that earthworms leave the soil when it becomes waterlogged (because their burrows fill with water) and go in search of drier (ie higher ground). When they come across a Tupperware water container in the chookery or the water tubs in the boy's feeding pen they must crawl upwards, ever upwards until they get to the top. Whether they just keep going or they lose their grip and fall in I don't know.
But what I do know is that each of the tubs will need to be emptied - yeah just what we need more water flowing into and across the ground - because neither the boys nor the girls will drink water contaminated as it now is by these little wormy bodies.