A spy plane with flapping wings and the size of a bee is being developed by at research team at the University of Bath.
The planes could be used in times of war and peace
The plane could send back video footage of battlegrounds and remove the need for human scouts.
It could also be used for wildlife surveys, fire and rescue operations and the detection of hazardous substances in peacetime.
A prototype could follow in "a couple of years" if the research works.
Dr Ismet Gursul, head of the aerospace research group at the University of Bath, told Reuters: "We are looking for the most efficient way of flying, and the rapid flapping of a flexible wing is one of these.
"In this respect we are imitating nature and the flight of
insects and birds."
The planes could also land on the roof of enemy vehicles and mark them for future attack or as carriers of chemical or biological weapons, say researchers.
The team says it realises the project will be tough as small aircraft are
vulnerable to high winds.
Dr Gursel said: "The smaller an aircraft is made, the slower
is its speed and the more it is vulnerable to high winds.
"This means that existing micro air vehicles can only fly for short periods
at low speed and are too large to carry out fine manoeuvres."