It is a myth that Alka Seltzer and other gas-generating substances cause seagulls to explode. Since seagulls can regurgitate the contents of their stomachs, they can eliminate unhealthy food sources before they cause any damage.
The urban legend involving seagulls and Alka Seltzer suggests that the foaming and gas production from a tablet will cause the bird's stomach to expand and eventually lead to it exploding. Proponents of the myth contend that seagulls' inability to pass gas means they cannot tolerate the Alka Seltzer. However, seagull biology contradicts this assertion. Similarly, birds do not explode when they eat uncooked rice kernels.