Swarms in nature have always intrigued humans because individually the animals or the insects do not appear to have intelligence but in a swarm, they are able to move as a cohesive intelligent formation capable of taking actions befitting an intelligent life form. Some of the world’s largest swarms in animal kingdom include mosquitoes, Argentine Ants, Christmas Island Crabs, krill, springbok, and locusts. Peter Miller, in Swarm Theory brings out that swarm intelligence works because of ‘simple creatures following simple rules, each one acting on local information’ and also that, a smart swarm is a group of individuals who respond to one another and to their environment in uncertainty, complexity, and change.
The use of swarms in warfare has been observed for over 2000 years, some examples include:
- Battle of Alexandria Eschate, 329 BC Scythians – mounted Archers,
- Battle of Carrhae, 53 BC Parthians – mounted Archers
- Battle of Khambula, 1879 Zulus – Dismounted light infantry armed with spears
- Battle of Britain, 1940 – Air Battle of Sept 15, 1940 British single-seat Spitfire and Hurricane fighter Aircraft
- Battles for Objectives Moe, Larry, and Curley, Baghdad, Operation Iraqi Freedom, 2003 Iraqi and Syrian light infantry.
Swarming has also been looked in to by US Military institutes in academic studies and war games. RAND has studies by John Arquilla and David Ronfeldt, ‘Swarming and the Future of Conflict’, 2000; Sean J.A. Edwards, ‘Swarming on the Battlefield: Past, Present, and Future’, 2000; and Sean J.A. Edwards, ‘Swarming and the Future of Warfare’, 2005. In the last document, the author has opined that:
- Swarming occurs when several units conduct a convergent attack on a target from multiple axes. It involves pulsing where units rapidly converge on a target, attack it, and then disappear.
- Swarming is of two types, one where units arrive on a battlefield as a single mass, disassemble, and attack the enemy from many directions, and the second, where the dispersed units converge and attack without forming a single mass.
- Five variables are essential for a swarm attack to be successful these are, superior situational awareness, elusiveness, standoff capability, encirclement, and simultaneity.
A new approach to achieve coordination amongst a system of large number of simple robots has emerged during biological studies of swarms in nature as well as during applications of Artificial Intelligence in to mechanical swarms it is called ‘Swarm Robotics’. Ant robots are swarm robots that communicate via trail of markings, for example, heat, odor, light, chemical substances, and transceivers.
Microbots is a generic term applicable to very small robots spanning robots of sizes from, small robots (<100 cm), minirobots (<10 cm), milirobots (< 1 cm), microbots (<1 mm) to nanobots (
- Symbiotic Evolutionary Robot Organisms, ‘Symbrion’. This project is funded by the European Commission. It is inspired by the biological world. Its aim is to develop a framework in which a homogeneous swarm of miniature interdependent robots can co-assemble into a larger robotic organism for problem solving. It has its roots in previous two projects called I-SWARM and SWARMROBOT.
- 3D printing of microbots. Engineers at Harvard have developed an ingenious layered folding 3D printing process by which it is feasible to mass-produce robotic insects. The size is <2.5 cm in diameter and <0.25 cm in height. Many such pop up microbots can be printed from a single sheet.
- Kilobot (Self-organizing thousand-robot swarm). Another project undertaken by engineers at Harvard aims at providing a simple platform for enactment of complex behaviors using 1024 small robots or Kilobots. It has been heralded as a stepping-stone in development of collective artificial intelligence.
All of the above projects and many more on similar lines have been funded by military R&D agencies including DARPA. All have military applications as is evident from the fact that the U.S. Military is looking at incorporating roles for swarms in its transformation programs. These swarms of intelligent UGVs, UAVs, and UUVs are intended to sense, recognize, and adapt to the changing situation. The sensor networks will be self-aware, self-healing, and self-defending.
In October 2015, US Army tested swarms of commercial off the shelf drones for applications in the military. Barry Hatchett of the Army’s Program Executive Office for Simulation, Training, and Instrumentation stated, “It has been proved that consumer [drones] can be used for intelligence, surveillance and reconnaissance, distraction tactics and, in the future, the ability to drop small munitions.”
In a landmark trial, this year the US Navy’s Low-Cost UAV Swarming Technology (LOCUST) program aims to have thirty drones flying together without having to be individually controlled, maintaining separation safely like a bird swarm. The operator would be piloting the whole swarm as a single unit instead of controlling individual UAVs. The trial would have far-reaching impact upon future of swarm warfare in the US armed forces.
The day is not far when the battlefield would graduate from ISR microbot swarms to weaponised microbot swarms carrying new age explosives delivered ingeniously into the enemies heart. The technology would leap frog to provide counter swarms as also counter-counter swarms. The era of the small and many appears to be dawning on the battlefield.
“I need a stealth bomber that’s going to get close, and then it’s going to drop a whole bunch of smalls – some are decoys, some are jammers, some are ISR [intelligence, surveillance, and reconnaissance] looking for where the SAMs are. Some of them are kamikaze airplanes that are going to kamikaze into those SAMs, and they’re cheap. You have maybe 100 or 1,000 surface-to-air missiles, but we’re going to hit you with 10,000 smalls, not 10,000 MQ-9s. That’s why we want smalls.” – Colonel Travis Burdine, USAF
 US Army’s future unit of action UA, US Navy’s After Next, and US Air force’s Global Strike Force programs.