Doodlebug

The term doodlebug is a word of uncertain origin that is used in a number of unrelated ways. Often it is a nickname applied to diminutive types, such as small airplanes or cars. It is also used in specific ways:

Railroads

In the United States, doodlebug was the common name for a self-propelled gas-electric railroad car. Such a coach typically had a gasoline-powered engine which provided electricity to traction motors on the vehicle, which drove the axles.

Doodlebugs sometimes pulled an unpowered trailer car, but were more often used singly. They were popular with some railroads during the first part of the 20th century to provide passenger and mail service on lightly-used branch lines, obviating the need to operate conventional trains consisting of a locomotive and coaches.

See also: Steam dummy

Insects

A doodlebug is the larvae of the ant lion, and sometimes any insect that goes backwards.

Weaponry

Doodlebug was a nickname to the V1 flying bomb