Once familiar with humans, urban European herring gulls show little hesitation in swooping down to steal food from the hands of humans, although a study conducted in 2019 demonstrated that the gulls are more averse to snatching food in proximity to humans if the experimenter made eye contact with the bird. During the breeding season, the gulls also aggressively 'dive bomb' and attempt to strike with claws and wings (sometimes spraying faeces or vomit at the same time) at humans that they perceive to be a threat to their eggs and chicks —often innocent passers-by or residents of the buildings on which they have constructed their nests. Large amounts of gull excrement deposited on property and the noise from courting pairs and begging chicks in the summer is also considered to be a nuisance by humans living alongside the European herring gull.