It is not advised to feed celery to snails as it's been known to kill them.
Some are but there are also male snails
see snails also have shells
Birds are perhaps at the top of the snail's predator list, but they are not the only ones who eat snails, fish, other snails, and humans also eat snails.
Generally snails are not predators, but there is one species that I know of that is a definite predator. The Assassin Snail, or Clea helena, is a freshwater snails that eats other snails and worms. There are a few other carnivorous snails in the Neogastropoda family also.
The snails typically used to make escargot are Helix pomatia, also known as Burgundy snails.
To safely introduce snails to a tank with betta fish, acclimate the snails to the tank water temperature, ensure the snails are healthy and free of parasites, and monitor the betta fish for any aggressive behavior towards the snails. It is also important to provide hiding spots for the snails to retreat to if needed.
Pound snails or giant African snails eat a variety of fruits and vegetables. They also eat the leaves of many trees or even grass.
Lobsters and Crabs, octopus, Sea Anemones, and sea spiders eat snails in the ocean. A variety of fish also eat snails in the ocean.
Also known as bladder or pond snails, they live in stagnant or slow moving water.
Aquarium snails are different from regular land snails. All aquatic snails have gills. Just like their land relatives, these snails also have radula(rasping tongue),tentacles, and hard shells. Aquatic snails do not have as developed eyes as land snails. Many aquatic snails have a door or an opcerium at the entrance of their shell. Some aquatic snails also grow to the size of a baseball.
Keep your snails in a tank filled with water. Snails, from the wild or not, will love to eat aquarium plants that are sold at any pet store. Also, don't keep the tank to clean, for they like to eat small amounts of algae off the tank walls. I also feed my snails shrimp pellets, which they love! Good luck taking care of your snails!
Snails do carry diseases! African land snails can harbor and pass on Meningitis and Schistosomiasis--a parasitic disease. They also are loaded with bacteria like salmonella and e-coli.