According to 20th century folklore, the laws of aerodynamics prove that the bumblebee should be incapable of flight, as it does not have the capacity (in terms of wing size or beats per second) to achieve flight with the degree of wing loading necessary. The origin of this claim has been difficult to pin down with any certainty.

The flight mechanism and aerodynamics of the bumblebee (as well as other insects) are actually quite well understood, in spite of the urban legend that calculations show that they should not be able to fly. In the 1930s, the French entomologist Antoine Magnan, using flawed techniques, indeed postulated that bumblebees theoretically should not be able to fly in his book Le Vol des Insectes (The Flight of Insects). Magnan later realized his error and retracted the suggestion. However, the hypothesis became generalized to the false notion that "scientists think that bumblebees should not be able to fly."

The calculations that purported to show that bumblebees cannot fly are based upon a simplified linear treatment of oscillating aerofoils. The method assumes small amplitude oscillations without flow separation. This ignores the effect of dynamic stall, an airflow separation inducing a large vortex above the wing, which briefly produces several times the lift of the aerofoil in regular flight. More sophisticated aerodynamic analysis shows that the bumblebee can fly because its wings encounter dynamic stall in every oscillation cycle.

One common, yet incorrect, assumption is that the buzzing sound of bees is caused by the beating of their wings. The sound is actually the result of the bee vibrating its flight muscles, and this can be achieved while the muscles are decoupled from the wings. This is especially pronounced in bumblebees, as they must warm up their bodies considerably to get airborne at low ambient temperatures. Bumblebees have been known to reach an internal thoracic temperature of 30 °C (86 °F) using this method.