I saw this snail in the creek. I'd never seen one like this before.
I fished it out so I could take a better picture of it.
I found these under the same leaf that had all the planaria under it. All the shells seemed to be empty, but maybe the snails were way deep down inside?
When I got home, I searched online to identify them, and I think they are Melanoidestuberculata. They are native to Africa and Asia, but in the 1930's they were brought to the USA for the aquarium trade, and since then, they have "escaped" and made themselves at home in much of the country.