Oak processionary Oak processionary The oak processionary "(Thaumetopoea processionea)" is a moth whose caterpillars can be found in oak forests. They are a human irritant because of their venomous setae (hairs), which can cause skin irritation and asthma. The moths are widely distributed in central and southern Europe, and are occasionally found as far north as Sweden. In the southern countries of Europe the populations are controlled by natural predators, but these predators do not exist in northern Europe. Their range is expanding northward, possibly or partly as a result of global warming. The moth now has an established population in the
Natural hazard human activity. Disease is a natural hazard that can be enhanced by human factors such as urbanization or poor sanitation. Disease affecting multiple people can be termed an outbreak or epidemic. In some cases, a hazard exists in that a human-made defense against disease could fail, for example through antibiotic resistance. Each of the natural hazard types outlined above have very different characteristics, in terms of the spatial and temporal scales they influence, hazard frequency and return period, and measures of intensity and impact. These complexities result in "single-hazard" assessments being commonplace, where the hazard potential from one particular hazard