Ticks have long been known as major nuisance pests of man and animals, but it was not until fairly recently that human tick-borne diseases in New Jersey were recognized as a significant public health threat. Examining the history of Lyme disease can demonstrate how development of residential communities within forested habitats may contribute to the emergence of these tick-borne diseases. Ticks are not uniformly distributed in nature, and even in seemingly ideal habitats, may be scarce or absent. Therefore, assessment of actual risk of acquiring a tick bite requires a good understanding of the nature of tick-borne diseases and of how to recognize tick habitats.