White Storks are a characteristic sight at their nests on tall buildings, such as church towers. They return to their nests in late winter (usually by January) and throughout the spring the typical sound of the bill-clacking that pairs make as a greeting ceremony can be heard. They travel to the grass plains to feed on reptiles, amphibians, large insects and even small mammals, carrying food back to feed to their young. The population of White Storks is so high that their bulky stick nests can also be found in trees, on electricity pylons and other tall man-made structures. Once the young have left the nests by mid-summer, the storks leave the towns and form small flocks on the plains. By the end of summer, some migrate to Africa, whilst others stay in the region, so it is possible to find White Storks all through the year.