I felt grateful for this windfall and made plans to gather a sizeable harvest and entertained, the prospect of driving down from the hills with a hefty shipment of worms. I even imagined becoming a night crawler baron as I counted out twelve hundred worms. At three dollars a dozen wholesale, I envisioned easy street as the next road I would be traveling. Nearby was an old bathtub. I placed my counted hoard into it and went down to a local mill to scrounge a load of sawdust mulch to bed them for the night. After tucking them in, I retired and figured at wholesale prices, I would gain a hundred fifty dollars the next day when I showed up at the fish camps just to the north in the Missouri Ozarks.
Upon awakening, I ventured to the tub and noticed some shriveled dried dark string looking things stuck to the rim. I thought that any escapees probably fried on the hot porcelain of the tub as they tried to leave their sawdust home. It did not seem I lost too many and I was still hopeful of a sizeable harvest. Digging into the sawdust to gather the remaining ones, I discovered it was unbearably hot in the middle of the pile, too hot even to run my fingers through it. Nary a worm survived my sawdust composting oven. Immediately I deflated, not only over the loss of income, but I suffered guilt that I was responsible for wiping out a whole colony of beneficial earthworms. I decided to abandon my fledgling empire and go back to seeking honest hard labor.
I had been introduced to my first lesson in spontaneous combustion. Composting materials can reach incredible temperatures at the core of their pile. As the moisture is driven off, sawdust can approach combustion temperature. The man at the lumber mill, told me that large piles of sawdust once ignited can smolder for long periods with out the slightest trace of smoke, but ready to bust into flame in the presence of a blast of air. He related that one time while moving a pile with a front end loader, it burst into flame as soon as he uncovered it. It was likely ignited by spark from his muffler and fed by sudden appearance of lots of air. I felt sorry about the worm’s fate, but gained respect for the heat generating properties of slow oxidation and its attendant risks.