Identification Pigeons roost in groups throughout residential neighborhoods, which is problematic because their feces quickly accumulate. Droppings collect on buildings, porches, sidewalks, and lawns. Similar in appearance to little marbles, pigeon droppings are firm and white-brown in color. The feces of healthy birds will contain tiny feathers. Loose, wet droppings are a sign of stressed or unhealthy birds. Problems Caused In addition to being aesthetically displeasing when they stain building facades, pigeon droppings are highly acidic and erode both stone and metal over time. If enough accumulates within homes, the pest's excrement can cause floors or roofs to collapse. Large amounts can also kill vegetation and contaminate food meant for both humans and livestock. Finally, pigeon droppings contribute to the spread of life-threatening diseases like psittacosis, cryptococcosis, and histoplasmosis. Removal To keep pigeon droppings off of private properties, individuals should use habitat modification and exclusion tools to reduce the possibility of attracting the pests. Frightening devices, bird spikes, and bird netting can all be employed to varying degrees of success. However, the most effective way to limit the presence of both pigeons and pigeon droppings is to call the wildlife experts at Critter Control.