People like Tri Tran, who fled Vietnam on a boat in 1986, showed up in San Jose with nothing, made it to MIT, and then founded the food delivery start up Munchery, which is valued at $ 300 million.

If parent birds use begging intensity to direct food to healthy offspring capable of vigorous begging, then parents should make food delivery decisions on the basis of their offsprings' calls.

The rise of food delivery has also played a role in the declining fortunes of the instant noodle industry.