Egyptian authorities detained a stork last week on suspicion of espionage, mistaking its migration tag for spying equipment. In fact the stork was innocent - like a number of other animals falsely accused over the years of undercover work, writes Mohamed Madi.

In 2011, Saudi authorities arrested a high-flying vulture on suspicion that it was flying missions for Israel's famously ingenious Mossad agency. And a spate of shark attacks near the Red Sea resort of Sharm el-Sheikh in 2010 was blamed by one TV station on GPS-controlled predators planted by Israel in order to harm the Egyptian tourism industry.

Iran has also felt threatened by animal agents. In 2007 the Iranian army arrested a team of 14 "spy squirrels" found near a nuclear enrichment plant. Officials said they succeeded in apprehending the suspects "before they were able to take any action".

However, not all reports of pets on patrol are as far-fetched as they seem. Animals have been serving in the military as early as 1908, when Germans first attached cameras to pigeons to take aerial photographs.

Some programmes have been more successful than others. The CIA's attempt to implant listening devices into a cat - dubbed Operation Acoustic Kitty - ended in failure on day one, when the kitty was run over by a car outside the Soviet embassy in Washington DC. The project was estimated to have cost more than $14m.

Another failed project was the equally outlandish Bat Bomb, tried by the US in WWII, where bats were strapped to mini-incendiary devices and dropped over Japan. The idea was for them to roost inside wooden Japanese buildings before bursting into flames. The atomic bomb ultimately proved more effective.