Yuan and his colleagues calculated that ducklings swimming directly behind their mothers would find it easier to swim. In contrast to swimming alone, the energy required is greater to produce waves.
“This is called wave resistance, and it restrains the movement of the ducklings as they swim. But the wave resistance is reversed for ducks that are in the sweet spot (behind the mother). They feel a push instead of a pull,” said the statement quoted from the sciencenewsforstudents page, Tuesday (16/11/2021).
The ducklings share the waves with their other sibling in tow. So all the ducklings seem to get a free ride from the waves created by their mother. However, if it is too late to swim to follow its mother, it will be far behind because it missed a ride.