On their own the birds, which each weigh about 80 grams (three ounces), are not much danger. But when flying in flocks so dense they can block out the sun, they are a hazard
The Italian League for the Protection of Birds (Lipu) patrols the city's streets playing loud noises to frighten the birds away. One of the noises is a recording of the starlings' own distress call, amplified hundreds of times
Blasting noise at dusk for three days causes many birds to fly away, but many remain. Others move on to different parts of the city where the process begins again