It became really apparent during the rains last week.
Snails crawl up the walls and plants around our patio, and appear to wait to die there. We’ve moved them back down to the soil, and they climb up again.
Kathryn remarked at the army of snails on the garage wall, beneath a bird feeder . . . that was the clue.
I don’t think ours do that eye-stalk thing. Worse for the parasites, most of the birds ignore the snails.