Bird & Pigeon Spikes.

Bird repellent spikes create a physical barrier to stop a bird or Pigeon from landing. Deterring birds from sills and ledges can be a big problem. However, you don't have to spend a fortune and with a little DIY, you can prevent birds from congregating. The fire gel product really works and lasts for many months. Or you can invest in an electronic bird repeller to keep pigeons off balconies etc.
 

Bird and Pigeon spikes are very effective.These moulded plastic strips are easily fixed to ledges and windowsills. If a bird or Pigeon can't put its feet down on a solid surface, they won't land and so so fly away. It's a simple solution to repel birds.