The Eurasian Wren feeds almost exclusively on small insects and spiders. It forages stealthily low down in the foliage, among moss and around upturned root plates and brush piles, using its slender bill to pick tiny creatures out of nooks and crannies. In winter the availability of insects can be the limiting factor for survival. Because it depends so heavily on insects, the wren is hit hard by long cold spells, and the population can fall sharply after severe winters.