Ive had a single apple snail in a tank now for over a year.....last week i found a clutch under the hood of the tank...never had another snail in that tank....are these fertilized or not??/ will snails lay empty eggs?
Females can store sperm like livebearers, but a year would be too long for the sperm to survive. The eggs will most likely be duds. They do lay eggs even if they aren't fertilized, like chickens. So you were right with your theory