The U.S. Navy has revealed it is retiring its group of mine-seeking dolphins, in what will be the end of an era for human-animal military relations.
When the dolphins are replaced by unmanned, torpedo-shaped 'knifefish' underwater robots in 2017, the marine mammals will join a long list of species recruited to help out scientists and the military over the years.
From cockroaches to cats, dogs, sea lions and even bats, military chiefs will try almost any animal species to give themselves the edge in combat and espionage situations.
Yahoo! News UK takes a look at the surprisingly large range of animals which have been 'recruited' in the name of war.
BOMB-CARRYING BATS (SECOND WORLD WAR, 1942)
During the Second World War, Britain and the U.S. hatched a plan to use bats to carry incendiary devices against Japan.
They reasoned that bats travel in large numbers and can carry more than their own body weight in flight.
Their ability to fly in darkness and seek out secretive places was also seen as a plus.
The project was submitted to the White House in 1942 and approved by President Roosevelt, but early tests were not successful. On one occasion, the bats set fire to a military airfield in New Mexico after being accidentally released.
Officials were to cancel the project in 1944 due to a combination of delays and over-spending.
PROJECT ACOUSTIC KITTY (COLD WAR, 1960s)
At the height of the Cold War, the CIA attempted to spy on the Kremlin by using a surgically-modified cat.
In a project which took five years to design, 'Acoustic Kitty' had a battery and microphone attached into its body, and an antenna into its tail.
The idea was that the cat would record and transmit recordings once planted in Soviet embassies.
Unfortunately, after surgery and training which cost the CIA more than $20m, the project was cancelled after the cat's first live trial when it was run over by a taxi.
SUICIDE BOMBER DOGS (SECOND WORLD WAR, 1940, IRAQ WAR, 2005)
Various nations have made attempts to use dogs to carry bombs, with limited success.
Soviet forces attempted to use 'suicide bomber dogs' in World War Two, but the plan was abandoned as the animals struggled to tell the difference between German and Soviet targets.
U.S. forces trained 'anti-tank dogs' strapped with explosives towards the end of the Second World War, but never used them. The animals were also unsuccessfully used by Iraqi insurgents in 2005.
POISON-DETECTING CHICKENS (IRAQ WAR, 2003)
The U.S. marines' deployment of Kuwaiti Field Chickens (yes, that's KFC for short) may have sounded far-fetched, but was deadly serious.
Marines bought 43 chickens which they planned to deploy on their Humvees to detect poisonous gas, in a similar way to how coalminers used canaries underground.
High ranking officers said it was 'one of the best ways we have of detecting chemical agents', but unfortunately within a week of landing in the Gulf, all but two of the chickens had died from illness.
SEA LIONS OF WAR (PERSIAN GULF, 2003)
The U.S. Navy used the specially-trained troupe of sea lions to protect warships from attacks from underwater saboteurs and mines.
Used for their intelligence and swimming speed (they can reach 25mph underwater), the sea lions patrolled harbours underwater using their acute directional underwater hearing.
They were trained at the U.S. Navy's Marine Mammal Programme to detect mines and attach grabber devices where necessary, despite the protests of animal rights campaigners.
KAMIKAZE CAMELS (1980s)
During their war with the Russians in the 1980s, Afghanistan's mujahideen would regularly send explosive-laden camels towards enemy positions.
When the animal wandered near to troops or equipment, they would detonate the explosives, causing multiple casualties and damage.
More recently, U.S. troops in Afghanistan were warned in 2001 that insurgents could use similar tactics once again.