At Home - Bill Bryson [133]
Clambering among the bed mites, on a much more gigantic scale, might also these days be lice, for it appears that these creatures, once nearly vanquished, are making a comeback. Like rats, lice come in two principal varieties: Pediculus capitas, or head lice, and Pediculus corporis, or body lice. These latter (familiarly known as cooties, probably from the Malay term kutu) are relative newcomers on the bodily irritants scene. They evolved sometime in the last fifty thousand years from head lice. Of the two, head lice are much smaller (they are about the size of a sesame seed, and actually look much the same) and so harder to detect. An adult female head louse will lay three to six eggs per day. Each louse can live for about thirty days. Lice eggs are called nits. Lice have developed an increasing resistance to pesticides, but the greatest reason for their increase, it seems, is low-temperature wash cycles in washing machines. As Dr. John Maunder of the British Medical Entomology Centre has put it: “If you wash lousy clothing at low temperatures, all you get is cleaner lice.”
Historically, the most common bedroom dread was bedbugs—Cimex lectularius, as the little blood suckers are scientifically known. Bedbugs made sure that no one ever slept alone. In former times, people were driven half mad by bugs and the desire to be rid of them. When Jane Carlyle discovered that bedbugs had invaded her housekeeper’s bed, she had the bed taken to pieces and carried to the garden, where each piece was washed with chloride of lime, then immersed in water for two days to drown any bugs that survived the disinfectant. The bedding meanwhile was taken to a sealed room and dusted repeatedly with disinfectant powder until no more bugs emerged. Only then was it put back together and the housekeeper allowed to resume a normal night’s sleep, in a bed that was now almost certainly at least mildly toxic to her as well as to any insect life that dared to creep back in.
Even when beds weren’t actively infested, it was routine to take them apart at least once a year and paint them with disinfectant or varnish as a precaution. Manufacturers often advertised how quickly and easily their beds could be dismantled for an annual maintenance. Brass beds became popular in the nineteenth century not because brass was suddenly thought a stylish metal for bedsteads, but because it gave no harbor to bedbugs.
Like lice, bedbugs are making an unwelcome comeback. For most of the twentieth century they were virtually extinct in most of Europe and America thanks to the rise of modern insecticides, but in recent years they have been vigorously rebounding. No one is sure why. It may have something to do with more international travel—people bringing them home in their suitcases and so on—or that they are developing greater resistance to the things we spray at them. Whatever it is, they are suddenly being noticed again. “Some of the best hotels in New York have them,” the New York Times quoted one expert as saying in a report in 2005. The Times article went on to note that because most people have no experience of bedbugs and don’t know what to look out for, they are likely to discover they are infested only when they wake up and find themselves lying in a swarm of them.
If you had the right equipment and a peculiar measure of motivation, you could find numberless millions of dinky creatures living with you—vast tribes of isopods, pleopods, endopodites, myriapods, chilopods, pauropods, and other all-but-invisible specks. Some of these little creatures are practically ineradicable. An insect named Niptus hololeucus has been found living in cayenne pepper and in the cork stoppers of cyanide bottles. Some, like flour mites and cheese mites, dine with you pretty regularly.
Move down to the next level of living things, to the world of microbes,