And when it comes to sniffing out moles even James Bond couldn't match them. Licensed to kill? "No, these boys are licensed to smell," revealed a source deep inside the counterespionage community. The key to the gerbil's unique role in tackling fanatics bent on world domination is its acutely powerful nose that can scent a whiff of treason in seconds. It does this by detecting a rise in adrenalin, the chemical released in sweat when humans are under stress.
   MI5 were so impressed that they once toyed with setting up a special squad of the furry creatures in the 1970s at the height of the Cold War.
   The plot was admitted by Sir Stephen Lander, Director-General of the Security Service, during a rare public appearance on Friday. The service's Canadian counterparts were first to discover the gerbil's skill and the Israelis had put it to the test, he told a group of assembled historians at the Public Records Office in Kew, south west London. The tiny four-legged agents were stationed in cages next to security check areas at Tel Aviv airport and carefully-placed fans wafted the scent of a suspect's hands towards their nostrils.
   Thanks to intensive training, the gerbils would press a lever if they smelled a rat — or detected increased adrenalin, as the technical backroom boffins say.
   The new boys were cheaper to run than traditional 007-style agents, too. Forget vodka martinis and Aston Martins. Just some fresh sawdust and a well-oiled treadmill kept them happy. Despite all this, MI5 abandoned plans to put the animals on active service after the Israelis discovered one fatal flaw — they could not tell the difference between desperate terrorists and ordinary passengers who were just scared of flying.

THE short, secret role of gerbils in the hunt for suspected hostile infiltrators was revealed by the head of MI5 yesterday. Sir Stephen Lander, Director-General of the Security Service, who was once head of MI5's registry of files, recalled seeing a file which described the special sniffing qualities of the domestic rodent. An MI5 man came up with the idea in the 1970s of using gerbils to detect nervous people arriving at airports. Apparently the Canadians had found that gerbils had such a powerful sense of smell that they could detect the slightest whiff of adrenalin, the chemical released in sweat when human beings are under stress.
   Sir Stephen, who revealed the tale of the gerbils during a private conference at the Public Record Office in Kew, said that the idea was that rodents were kept in cages and concealed fans wafted air across a suspect's hands towards the animals' nostrils. If the gerbils started to lick their lips at the thought of tasting the salt in the excreting sweat, it would give the game away and the suspect would be led away for further interrogation.
The secret plan was dropped after an experiment at a foreign airport in the 1970s showed that the gerbils were far too sensitive to be operationally effective. Passengers were found to be nervous for all sorts of reasons, including suffering from the aftermath of the fear of flying.
    The file on the gerbils contains three pages and is classed as a "policy" document. It is known as a "shut file" because MI5 feels that it no longer has any need to consult it for future operations. However, the file remains in MI5's archives and will not be released for general consumption until the 1970s files are examined for handing over to the Public Record Office.
    Sir Stephen's recollection of the gerbils' brief role in intelligence operations came as he spoke of MI5's policy towards releasing secret files. Addressing historians interested in the publication of MI5 records, he told his audience: "The good news is that our files are safely secured and stored in good condition. The bad news, given that the service has worked continuously for over 90 years, is that there is rather less material than you might expect." "There are 400,000 paper files, many multivolume. There is one volume on the security uses of gerbils compared with six on vetting procedures. Many of them are still living entities that record the lengthy interest of the service over decades in a single subject, organisation or individual. Much of our work has long antecedents, knowledge of which is important to our success today.' That was the reason, he said, that files dating back 50 years or more often remained closed when related papers from other government departments were made public. He confirmed that files would eventually be made available on eminent public figures and those involved in important historical events. A small percentage of files on individuals who turned out not to be suspicious was also being kept for future historians, but they would be released when they could not be an embarrassment to the people concerned.
    A small team of retired agents is working through the files deciding what it is safe to put on view, but they are not expected to complete work on the period up to the end of the Second World War for another three to four years. Some files have been released and more are due later this year, including material from the 1920s and 1930s when the agency's total staff was fewer than 20. The gerbil file will have to wait, along with the huge volume of other material from the Cold War, until after that.
   Sir Stephen also revealed that MI5 has a programme for videoing and taping interviews with former agents to give a personal flavour to the paper files. The conference was titled The Missing Dimension, a reference to the lack of publicly available intelligence material. Sir Stephen said: "I do not believe that anyone could claim that Intelligence has been totally absent from 20th-century historical studies and that applies to peace as well as wartime material."
   MI5 had been transferring files to the Public Record Office for public release since November 1997. The first tranche comprised surviving records from the First World War. Since then, there had been a further six tranches, totalling 708 files, largely related to the Second World War, although many files contained prewar material. Sir Stephen said: "There is material in our archives which will add to historians' understanding of 20th-century history. In particular, how successive governments and the Security Service approached non-military threats."

MI5 planned to recruit a team of trained gerbils to help expose undercover agents, according to the security service's director-general. The rodents were to play a key role in the interrogation of suspects because their acute sense of smell meant they could detect a rise in adrenalin, the chemical released in sweat when humans feel under stress.
   Sir Stephen Lander revealed details of the gerbil files during a rare appearance at a conference at the Public Record Office in Kew. Sir Stephen said research for the Royal Canadian Mounted Police in the 1970s had uncovered the gerbil's skill and the Israelis had first put it to the test. They had kept the rodents in cages next to security check areas in Tel Aviv airport. Carefully placed fans wafted the smell of a suspect's hands towards the animals' nostrils. The gerbils were trained to press a lever if they detected increased adrenalin.
    But MI5 abandoned its plans to use the gerbils after the Israelis discovered that the gerbils could not tell the difference between terrorists and passengers who were scared of flying. At Kew, a team of retired agents is working through some 400,000 files produced by MI5, deciding which are safe to put on public view.
    Material from the 1920s and 1930s is due to be declassified later this year but the team are not expected to complete work on the period up to the end of the Second World War for another three to four years.