Silly String, that colorful hazard of Halloween haunted houses and kids' carnivals, is more than just a sticky party favor. For soldiers in Iraq, it has also been a safety tool.

Though it’s not an official tool supplied by the U.S. military, soldiers working in Iraq have found the lightweight, shooting string useful in detecting Improvised Explosive Devices (IEDs). The adhesive, resin-based material gets caught on trip wires but isn’t heavy enough to move them. That means soldiers can shoot the string—up to 12 feet—across a room to detect the explosive traps without setting it off. If the Silly String stays suspended in the air, instead of just falling to the ground, they know the area isn't clear.

Marines serving in Iraq have been requesting cans of the spray putty since at least 2004, when the 1st Marine Expeditionary Force asked for two dozen cans to take to the Middle East. In 2007, a New Jersey woman whose son was serving in Iraq collected 80,000 cans of the stuff to send to troops. However, she struggled to ship the cans for a full year, since aerosols are considered hazardous materials and can’t be mailed through many companies. While the Silly String did eventually make it to the Middle East, it was such an arduous process that she didn’t attempt to repeat it.