It is not true that Alka Seltzer and other things that make gas make seagulls explode. Since seagulls can throw up what’s in their stomachs, they can get rid of sources of unhealthy food before they do any harm.
The urban legend about seagulls and Alka-Seltzer says that the foaming and gas made by a tablet will cause the bird’s stomach to get bigger and bigger until it explodes. People who believe this myth say that seagulls can’t take Alka Seltzer because they can’t pass gas.
But the biology of seagulls goes against this claim. In the same way, birds don’t blow up when they eat raw rice kernels.