Some birds can present serious problems when not controlled and spread diseases. There is much legislation surrounding the control of birds.
Bird droppings are particularly unpleasant, being infested with disease causing organisms and creating slip hazards. In addition, the droppings are unsightly and can cause serious structural damage to buildings.
Nesting materials and feathers often contain many insects, which can lead to secondary infestations of properties. Birds' cooing and screeming cries, such as those of the seagull, cause major unrest.
In addition, birds such as sparrows, starlings and pigeons can cause economic losses to food-related businesses by fouling and eating the food products being made or stored.