I've found plenty of slugs hiding among the lower looser cabbage leaves but nary an earthworm. If I find earthworms in those looser leaves near the stem then they'd be up there hiding from the moles ;-)...or they are climbing up there trying not to drown in rain saturated soil as others have mentioned. Maybe it's the variety of cabbage grown? Mine are all tightly packed hard heads that earthworms can't easily penetrate, other than the small gaps closest to the root/stem. Looser head varieties offer critters more places to hide. If I grew loose heads here we'd be dining on Slug & Cabbage stew......Yeah, I know this thread is old like me but I'm snowbound inside today, so what the hey.

Yup... Nightcrawlers have been decimating my carrot seedlings for a couple of years now. I have ruled out other things such as slugs, damping off, earwigs etc. I mulch my garden pretty heavily, but the carrot beds were intentionally left clean to avoid competition for the emerging seedlings.. The poor worms were just hungry. They came up, looked around - nothing to eat except carrot seedlings - oh well, better Garth's carrots than nothing... chomp - chomp - replant - chomp - chomp... So I started mulching the bed with grass clippings and more seedlings survived. Ready to do war again this year. Perhaps I will string bright lights over the carrot bed. I simply have too many worms in my ultra rich organic soil. They know a good thing when they find it. I have photos of the stockpiles of debris over their holes. Amazing critters.

I think I would wet/dry vac them up before they dried. Try plugging up the drain holes with someting that will allow water to drain like bronze wool, landscape fabric or similar. More likely they are crawling under the sliding door sills. Caulk the track at the slab. Make an effort to see how they are getting in. Take a beer or glass of wine and spend some recon time on your patio when it rains. I thing John was thinking to attract birds that also might eat the worms. A chicken or 2 would probably have a feast & learn where to go when it rains for the treat.

Oddly enough to many gardeners, earthworms are heavily implicated in a number of serious negative impacts on our native plant communities, at least up here. In short, the glaciers removed all earthworm species from vast swaths of N. America and all-yes- all of those worms you see in places like this are invasive species! Florida of course did not get glaciated but that doesn't mean those big European nightcrawlers belong there......or whatever worms you may be finding. This is an emerging topic and I admit to being on the fence about some aspects of it, but earthworms are held in a much dimmer light in some circles than the average gardener might imagine. People dumping their leftover bait after fishing is thought to be one means by which this has happened, and in that case mea culpa. Not these days but long ago.