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. American Dog Ticks can be identified in any of their three life stages: larvae, nymph, and adult. These ticks are most commonly found in leaf litter or tall grass. The larvae have six legs and when newly hatched are yellow with red markings near the eyes. Shortly before transforming into a nymph, the larvae are slate-gray to black. Once a larvae transforms into a nymph, it has eight legs and is dark brown in appearance. The adult female ticks can be identified by their large off-white scutum against a dark brown body. The adult males lack the off-white scutum but have a mottled gray coloration along their backs (text from: http://labs.russell.wisc.edu/wisconsin-ticks/tick-surveillance/).