Pigeons are a relative of the Rock Dove, all efforts throughout the world have failed to stop the increase of the feral pigeon. Given the right conditions, they breed throughout the year, at an incredible rate.
Feral pigeons have been described as Flying Rats. Their excrement has been known to harbour all sorts of diseases, mites and fleas. Favourite nesting sites are balconies, ledges, flat roofs, lofts and empty buildings. If they get into a loft /roof space, because of a broken tile, the build up of guano can be considerable, as they breed so quickly in these conditions.