Controlling pigeons on the exterior surfaces of buildings often requires considerably more effort. The most effective and permanent methods of control involve structural modifications which either physically exclude pigeons from the preferred surface or make it difficult for the birds to rest comfortably on the exposed building surfaces. Physical exclusion can be accomplished by installing weather resistant netting, wire screening, sheet metal, or other materials in a manner that will restrict access to the roosting sites. A grid of heavy gauge monofilament line spaced at six-inch intervals may also be used to create a fence that will interfere with the birds' normal flight pattern to the roosting area. The needle-like strips of stainless steel act as a prickling fence to exclude birds permanently without harm.
Pigeons prefer to roost on level surfaces.
Roosting areas can be modified to create a sloping surface, at a 60 degree incline or more, by installing wire mesh or other material to eliminate the level surfaces. There are also a number of non-toxic sticky substances registered as tactile repellents for bird control efforts. Birds tend to avoid landing upon treated areas but the effectiveness is usually lost over time. Although time-consuming and unpleasant, removing nests will help depress populations. Nest destruction must be followed by pigeon-proofing the structure to achieve maximum population control.