Myth: Birds die from eating wedding rice
Reality: The temperature inside the bird never gets hot enough to cook and swell the rice. If you’ve ever cooked rice, you may remember how the rice just sits at the bottom of the water pot until you raise the temperature enough to start cooking the rice. In short, the rice would need to be cooking to expand, and that would give the birds something much more important to worry about.
Source: https://thebestschools.org/magazine/25-popular-science-myths-debunked/