When I visited the town of Belo Blato, about 60 kms from Belgrade, I was a bit taken aback by these odd-shaped 'haystacks'. They are not haystacks at all, but rather bundles of reeds that are later sold for roofing on various structures.
Here's a link for you. Notice that this industry has been around a long time and that it is a fact that insects do not attack the reed stem, hence making then perfect for roofing.
See other skies on SKYWATCH.