Why Frogs Sometimes Fall From the Sky

Animal rain, a rare phenomenon where animals fall from the sky, has been reported since ancient times. Documented cases include frogs in Serbia and fish in Australia. While some incidents have simple explanations, like spider ballooning or fireworks startling birds, aquatic animal rain is harder to explain. Meteorologists suggest waterspouts, tornadoes over water, might lift and transport animals. However, this theory remains unconfirmed due to the difficulty of observing such events. The phenomenon often involves one species, possibly due to similar size and weight or dense clustering.

How do waterspouts contribute to the phenomenon of animal rain?

What is the significance of the observation that animal rain usually involves just one species?