There are several methods for tick surveillance including both active and passive methods. These include tick drags and tick collections from animals.
Active surveillance is used to determine whether a species of tick is established within a certain area. Researchers collect tick specimens using various methods including flagging or dragging, collection from host animals and trapping ticks in carbon dioxide baited traps. Passive surveillance includes specimen submission to public health departments or disease surveillance laboratories by veterinarians, physicians and the general public (text from: http://labs.russell.wisc.edu/wisconsin-ticks/tick-surveillance/).