What kind of snails do you want? Trapdoors are usually sold in the spring. Anyone who has aquariums or ponds would more than likely give them away. They are considered pests. I bought aquarium plants from Petsmart and trumpet snails came in on the plants..not happy about that. Contact your local aquarium forum. I'm sure people will be glad to give them to you. If you want apple snails, petsmart, aquabid, those kinds of places have them. Aquaria central people have them for sale all the time in their classifieds.