I see these tiny shells in my compost [seem to be empty] I thought they might be Decollate snails [prey on large brown garden snails], but the shape of the shell is different. But the Decollate is also said to eat worms. Do you see signs of these snail-like creatures eating your worms? When you squish these shells, are they empty? I hope someone with experience will answer you, as I'm curious, too.

They are definitely empty. I haven't seen any evidence of eaten worms, but I'm not sure I'd know what to look for. There are plenty of worms and they are eating up a storm and mating.

Thanks for the response!

The predatory decollate snail, Rumina decollata, has been released in Southern California citrus orchards to control young brown garden snails and is providing very effective biological control. It feeds only on small snails, not full-sized ones. Because of the potential impact of the decollate snail on certain endangered mollusk species, it can�t be released in California outside of Fresno, Imperial, Kern, Los Angeles, Madera, Orange, Riverside, Santa Barbara, San Bernardino, San Diego, Ventura, and Tulare counties. Decollate snails can feed on seedlings, small plants, and flowers and can be a nuisance when they cover the back patio on a misty day. Because snail baits will kill decollate snails, you shouldn�t use them where these predators are active.

Here is a link that might be useful: How to Manage Pests Pests in Gardens and Landscapes