Cliff swallows are a common nuisance to homeowners. According to the University of California Statewide Integrated Pest Management Program, cliff swallow droppings create aesthetic problems and their nests frequently contain mites and insects, such as swallow bugs, that commonly bite humans. Consider trying a variety of different exclusion tactics to stop the pests from building nests on your house.
Remove all bird baths or open water sources from your property. Cliff swallows build their nests in areas where water is readily available or easily accessible.
Locate and remove all nests from your house. Cliff swallow nests are gourd-shaped and mud-like in appearance and usually consist of sand, silt and clay, but may also contain grass stems or feathers. They are commonly found under the eaves of a house or near the highest point of an establishment. The University of California Statewide Integrated Pest Management Program recommends removing the nests by spraying or washing them down with water or by knocking them down with a pole.
Attach sheet metal, glass or Plexiglas over surfaces on your house where cliff swallows commonly build their nests. According to the University of Nebraska Lincoln, cliff swallow nests are rarely attached to metal or surfaces with slick surfaces like glass, Plexiglas or sheet metal.
Place netting over all nesting sites on your house. Netting will provide a physical barrier between the cliff swallows and their favourite nesting sites on your house. According to the University of California Statewide Integrated Pest Management Program, the mesh of the netting should be 1/2 to 3/4 inches in size to prevent the nuisance birds from squeezing through the netting and gaining access to your house. Attach the netting to the eaves, walls or siding of your house with a strong tape, hooks, staples or similar material.
Put bird spikes in areas where nesting sites are most prominent. Bird spikes consist of needle-like spikes and prevent birds from landing on or gathering near an object or area. The University of Nebraska Lincoln recommends placing bird spikes along the junction of your house walls and eaves for maximum success.
Actively remove all swallow nests from your house, and exclude the nuisance birds from your property on a regular basis to keep the nuisance birds at bay.
Cliff swallows are strongly attracted to old nests, so make sure you remove all mud or other material the nest was made from off your house. It may take a few days to properly remove the cliff swallow nests from your home, as the nuisance birds may persistently try to rebuild the nests multiple times after they have been destroyed or removed from your house.
Be aware that in many states it is illegal to remove cliff swallow nests that contain eggs or their young. Be sure to check with your state's wildlife department before removing cliff swallow nests from your home. Avoid trapping or shooting the nuisance birds or using toxicants to stop the pests from nesting on your house as it is against the law. According to the University of Nebraska Lincoln, the use of toxicants, trapping and shooting of cliff swallows is against the law as these particular species of birds are classified as migratory insectivorous birds under the Migratory Bird Treaty Act of 1918.