The golden apple snail (GAS) Pomacea canaliculata damages rice seedlings, resulting in uneven crop stand. GAS damage is characterized by missing hills and floating leaf fragments in the field. GAS cuts the base of young seedlings with its layered tooth (radulla) and eats the succulent leaves. The extent of damage to the rice crop depends on snail size, snail density, and growth stage of the rice plant. A density of three GAS m-2 causes significant yield loss, with much greater damage on direct-seeded rice and young seedlings transplanted at 18-21 d (Litsinger and Estano 1993). However, earlier investigators failed to consider GAS size when assessing damage to rice seedlings in either transplanted or direct-seeded rice systems.