When the enormous glass-covered Crystal Palace (built for the famous exhibition in 1851) became infested with sparrows -- with messy consequences for exhibits and exhibit-goers alike -- Queen Victoria urgently sought a solution.

Clearly, the birds could not be shot. Robert Paxton and the building's other designers were baffled. At last, the queen sent for the Duke of Wellington.

His advice? "Try sparrow-hawks, Ma'am."