You have had one mystery snail for a few months and you just found an egg sack how did reproduce?

Mystery snails are hermaphrodites, meaning they have both male and female reproductive organs. Although they can self-fertilize, they typically reproduce by mating with another mystery snail. However, if no other mystery snails are present, a single snail can still reproduce through a process called self-fertilization. This involves the snail using its male organs to fertilize its own eggs. The eggs are then laid in a gelatinous egg sack, which can contain anywhere from a few to several dozen eggs.