Some people love pigeons, some people hate pigeons – some feed them and some kill them. Emotions are bubbling without restraint. They are called “rats of the sky” but they also stand for hope and peace. In nearly every big city pigeons are a growing problem. Their corrosive excrement destroys buildings and sculptures and the diseases they carry are of great potential harm to humans. Communities and citizens are helpless in the face of their countless numbers. Scientists and enthusiasts are searching for solutions. Here are some pictures from the front of this battle.