This study investigated the ecology and biology of the golden apple snail in rice fields. Egg masses were produced at inconsistent intervals with the number of eggs per cluster ranging from 92 to 592 (mean 272). Regardless of clutch size, hatching success ranged from 87 to 100% (mean 95.8%). In the field, mating took place 82 days after hatching. Mean shell length at this age was 38.2 mm with females bigger than males in general. The male to female ratio was ~1: 5. Peat soils reduced egg mass production significantly and egg masses submerged in water for more than 1 week reduced hatching success significantly.