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Mud Swallows (Cliff Swallows)

**Wildlife Pests Require a Wildlife Professional & are NOT Considered Pest Control – We are providing this information as a service to our customers and would be happy to refer you to a wildlife control company to further assist you. **

While many people enjoy bird watching around their home, an entirely different experience can sometimes occur when mud swallow colonies attempt to make your home into their home.  Unlike most birds that nest in trees, mud swallows build their nests under overhangs such as eaves, porch roofs and awnings.  As their name suggests, their nests are built primarily of mud mixed with twigs and grasses and adhered to the exterior surface of the home.  Houses that are primary targets for mud swallow invasion are those that have easy access to a water source in which mud can be gathered.  Food supply is another important factor for mud swallows when determining a nesting location.  Mud swallows are frequently seen during summer months swooping through street intersections capturing miller moths and other insects.  Nests are constructed of roughly 900-1300 individual pellets of mud.  Pellets are gathered one at a time.  Nests are gourd shaped and have an entrance near the top that points downward.  The swallows tend to select the same or nearby nesting areas year-after-year which can lead to an increasingly large colony and multiple nests.

Several problems can occur with the nesting swallows.  Droppings are often a primary concern of residents due to the potential for disease, unsightly mess and damage that can result due to the uric acid in the droppings.  In addition, swallow colonies may become infested with swallow bugs.  A close relative to bed bugs, swallow bugs multiply quickly and may cause adults to abandon their nests leaving young to die if they are unable to fly.  Once the nests have been abandoned, it is not uncommon for residents to experience swallow bug infestation inside their home as the bugs search for a new food source.  Removing emptied nests and treatment will be necessary in order to eradicate the infestation.  The nests themselves can also create issues for some homeowners are scraping the nests down may result in damage to the exterior of the home.  Due to their mud construction, nests may need to be removed by using high pressured water.

Swallows are a migratory bird and are therefore protected by the Federal Migratory Bird Act.  Swallows are very persistent with their nest building attempts once a nesting site has been located.  Removing partial nests in an attempt to keep the swallows from nesting at a location can at times be a futile act.  Swallows are capable of constructing a complete nest within a short period of time. Nesting swallows may not be harassed or disturbed.  Once nests are completed, they cannot be knocked down or removed until the birds are no longer occupying them.  Once nests have been removed, exclusion methods are the best way to stop future nesting.  Metal flashing or bird netting installed diagonally between the eave edge and the side of the structure will reduce attractiveness of the site to the swallows by reducing or removing the shelter provided by the overhang.