The unconventional proposals were made by the US Air Force

Other weapons that never saw the light of day include one to make soldiers obvious by their bad breath.

The US defence department considered various non-lethal chemicals meant to disrupt enemy discipline and morale.

The 1994 plans were for a six-year project costing $7.5m, but they were never pursued.

The US Air Force Wright Laboratory in Dayton, Ohio, sought Pentagon funding for research into what it called "harassing, annoying and 'bad guy'-identifying chemicals".

The plans were obtained under the US Freedom of Information by the Sunshine Project, a group which monitors research into chemical and biological weapons.

'Who? Me?'

The plan for a so-called "love bomb" envisaged an aphrodisiac chemical that would provoke widespread homosexual behaviour among troops, causing what the military called a "distasteful but completely non-lethal" blow to morale.

Scientists also reportedly considered a "sting me/attack me" chemical weapon to attract swarms of enraged wasps or angry rats towards enemy troops.

A substance to make the skin unbearably sensitive to sunlight was also pondered.

Another idea was to develop a chemical causing "severe and lasting halitosis", so that enemy forces would be obvious even when they tried to blend in with civilians.

In a variation on that idea, researchers pondered a "Who? Me?" bomb, which would simulate flatulence in enemy ranks.

Indeed, a "Who? Me?" device had been under consideration since 1945, the government papers say.

However, researchers concluded that the premise for such a device was fatally flawed because "people in many areas of the world do not find faecal odour offensive, since they smell it on a regular basis".

Captain Dan McSweeney of the Joint Non-Lethal Weapons Directorate at the Pentagon said the defence department receives "literally hundreds" of project ideas, but that "none of the systems described in that [1994] proposal have been developed".

He told the BBC: "It's important to point out that only those proposals which are deemed appropriate, based on stringent human effects, legal, and international treaty reviews are considered for development or acquisition."