Bed bugs are mentioned in Greek writings as early as 400 years BCE, Aristotle mentions them later, and in a work by Pliny from the year 77, he claims that they can be used to treat snakebites, among other things. In Germany, they were first heard of in the twelfth century and in France around the year 1300. In Denmark, bed bugs arrived during the seventeenth century, by travelers, perhaps pilgrims, from the south. They quickly became common, were given many common names and soon a lot of superstition was attached to the intrusive guests. One of the more strange pieces of advice for avoiding bed bugs comes from Vendsyssel in Denmark and requires keeping a human skull from a grave in the farmhouse in order to never get bed bugs. It was also said that the bed bugs were displaced by the smell of a sheep, so in some areas the family had a sheep in an empty alcove, HP Hansen recounted in 1928.
Let us immediately state that bed bugs are not directly concerned with hygiene. As long as blood is available they do not care whether the house is clean or dirty.
In the 1930s, Denmark seriously set in against bed bugs. To limit the spread, many municipalities and property companies made demands for bed bug certification when people moved from one apartment to another. The apartment and the furniture were examined by a fumigator, and if bed bugs were found they had to be controlled before people were allowed to move. This contributed to getting the problem somewhat under control, and when effective synthetic insecticides, DDT among others, were available after World War II, bed bugs quickly became rare animals in Danish homes. For a long time, the number of cases was on a low and fairly constant level, but in the time from 1968 onwards, a steady increase in the number of problems with bed bugs could be noted. It was explained by the increase in travel and the relatively large number of migrant workers who came from countries with a warmer climate where the bed bugs were more common than in Denmark. The problems were kept reasonably at bay, primarily by means of the newly developed synthetic insecticides until the bed bugs over the past two decades have become increasingly difficult to control, not just in Denmark but wherever they occur. The most important explanation is undoubtedly the increasing resistance of bed bugs to the pesticides that are left.