![Mud nests made by a colony of cliff swallows. [W.P.Gorenzel]](http://ucanr.edu/blogs/UCIPMurbanpests//blogfiles/36152_original.jpg "Mud nests made by a colony of cliff swallows. [W.P.Gorenzel]")
However, during their migration, these birds may cause problems for occupants in urban areas. The birds may nest in colonies on buildings and other structures and their activities can be a nuisance.
Laws that Protect Birds
If migratory bird activities are causing issues in your building, make sure you know the law before you take any action. Certain birds that nest on dwellings may be protected under the Migratory Bird Treaty and Endangered Species Act. To learn more about exclusion of birds from structures and about the laws which protect them, read the blog article “Excluding Migratory Birds from Buildings”.