A homeowner can reduce a pigeon infestation on a balcony by installing low-voltage electric wires, using ultrasonic devices, applying non-toxic sprays, scaring the birds and using traps. To prevent pigeons from congregating, avoid storing food or garbage near the balcony, install anti-roosting spikes or strings to make roosting uncomfortable, and sprinkle pepper or cinnamon in the vicinity.
Pigeon droppings are unattractive, can damage the finish on buildings, and contain dangerous fungi and bacteria harmful to humans. Pigeons may carry diseases including encephalitis and salmonella and can transport, fleas, ticks and mites.
Homeowners may want to consider measures that completely prevent pigeons from congregating, such as adding screens and netting to the balcony and creating sloping surfaces where pigeons are likely to roost such as railing, awnings and over light fixtures. The homeowner should ensure that neither she nor her neighbors ever feed the birds.
To scare off pigeons, spray them with a water hose, use reflective tape or Mylar balloons, make loud noises with exploding party favors, or install a statue of an owl or other predator.
An ultrasonic device uses a combination of wave forms to create noise that interferes with the method birds use to talk to one another. The device does not scare the birds, but discourages them from flying into or spending time in the area.