True sparrows, the Old World sparrows in the family Passeridae, are small passerine birds. As eight or more species nest in or near buildings, and the House Sparrow and Eurasian Tree Sparrow in particular inhabit cities in large numbers, sparrows may be the most familiar of all wild birds

House sparrows are an increasingly common problem bird in urban areas. These small, quick, intelligent pest birds are predominantly small, plump brown-grey birds with short tails and stubby, powerful beaks. Sparrow legs and toes favor branch and wire perching and their short conical bills are ideal for cracking seeds and grain. Sparrows are very adaptable and have learned to nest in our structures and eat our scrap food.

Sparrows often gather in huge flocks to feed and roost, aggressively forcing other birds out of their territories. Sparrows prefer nesting in small enclosed places such as house shutters, drainage piping, building rafters and corrugated metal siding. These pest birds average about 20 offspring a year, allowing their numbers to increase rapidly to infestation levels.

Sparrows are noisy problem birds, especially when they congregate in large flocks. Besides the annoying noise factor, sparrow problems are often found in manufacturing and food processing plants. These areas are particularly appealing to sparrows for their variety of nesting and feeding sites. Sparrow nests cause flooding from backups in gutters and drainage pipes, as well as clog machinery and even start fires from nesting materials in machinery housings.

Sparrow droppings contain uric acid which is highly corrosive and can cause extensive damage to metals and other substrates it sits on for long periods. In addition, the bacteria, fungal agents and ectoparasites found in sparrow droppings and nesting materials are responsible for a host of serious diseases, including histoplasmosis, encephalitis, salmonella, meningitis, toxoplasmosis and more. Many companies also retain significant clean up and maintenance costs due to sparrow control problems they don't resolve.