Everyone likes to hedge their bets out here with good luck charms, religious medals, their lady's lingerie tucked under their helmets - and chickens.

On the front lines, guarding against a chemical attack by Saddam Hussein, are chickens, which serve the function of canaries in a coal mine. If they keel over, the troops know the area has been "slimed" - jargon for a chemical or biological attack.At one base, the chief chicken is Buford, and he sits in a cage next to a gas monitoring machine. Buford is the backup. If the machine fails, Buford won't. Even the base newspaper is called "Buford Talks."

At the front, military intelligence officers are saying Iraq's use of chemical weapons against them is no longer a question of "if" but "when." The jury is still out on whether Iraq ever learned how to put chemical warheads on long-range missiles like the Scuds. But there is no doubt that Iraq has bombs, artillery shells, short-range rockets mounted on trucks and short-range missiles fired from helicopters - all capable of carrying chemical payloads.

There are plenty of clues that Iraq intends to use them, including the movement of supply trucks to bunkers where chemical weapons are believed to be stored. The Iraqis have also prepared a half dozen decontamination sites in southern Iraq, not because they fear the United States will slime them back, but because they previously have experienced wind shifts that sent toxic clouds back to their own troops.

The allies have at least partially destroyed supply depots and chemical production facilities at Samarra, Falluja, Salman Pak, Musayyib, Iskandriyah, Baiji and Qaim. But before those attacks, according to intelligence estimates, Saddam Hussein built up a stockpile of 2,000 to 4,000 tons of lethal chemicals.

Western firms, including some in West Germany and even one in Baltimore, helped Iraq build this chemical warfare capability, according to a U.S. Customs Service investigation.

Mustard gas forms the bulk of the Iraqi chemical arsenal. It burns the lungs, blisters the skin and can be fatal in high doses. The more dangerous agents are the nerve gases known as tabun and sarin. One drop of sarin, inhaled or absorbed in the skin, can kill a person in as little as two minutes. Tabun takes about 15 minutes.

Saddam Hussein has scored big with chemical weapons against helpless civilians. But they are not an effective weapon of mass destruction against troops with protective gear. One U.S. military study shows that 95 percent of those hit by mustard and nerve gas in this century have survived. Sarin and tabun evaporate within minutes in the desert heat.

The greatest effect a chemical attack would have at the front would be to slow the advance of allied troops. And a chemical attack would complicate medical care.