Lyme disease, like many other zoonosis  It is transmitted by insects that carry the pathogen by sucking the blood of vertebrate hosts  Scientists have long thought that population density of white-footed deer is the best predictor of Lyme disease
The number of other species can also be used to predict the incidence of Lyme disease.
 However, a 13-year study of the ecological determinants of Lyme disease in a Lyme disease-prone area of southeast New York disproved this view, because in years of high Lyme disease incidence, populations of white-footed deer are generally lower than in years when the incidence of Lyme disease is low