Are pigeons good or bad to have around?

Whether pigeons are good or bad to have around depends on perspective, location, and whether you are talking about a few pigeons in a park or a large flock roosting on your building. Pigeons have good qualities, they are highly intelligent, able to recognize human faces and remember them for years, they are devoted parents that produce crop milk to feed chicks and form lifelong pair bonds, they have excellent homing ability and were historically used as messengers in wars saving lives, they eat insects and weed seeds, and their cooing can be soothing. In parks, a few pigeons are generally harmless and enjoyable to watch. However, pigeons can be bad to have around in large numbers on buildings because their droppings accumulate, stain buildings, sidewalks, and cars, can corrode stone and metal, and in large amounts can harbor fungal spores that cause histoplasmosis and cryptococcosis when inhaled during cleaning, and they can carry parasites like fleas and ticks. Large flocks can be noisy and their nesting materials can clog gutters. They can also attract predators like hawks. The bad aspects are mostly due to human feeding and poor waste management that cause overpopulation. So a few pigeons in a park are good and part of urban wildlife, but a large colony roosting on your building can be problematic and require humane exclusion like bird spikes and netting after confirming no nests with eggs.