According to the Centers for Disease Control and Prevention (CDC), there 8 species of ticks that are of public health importance to humans in the United States and at least one can be found in every state. There are many other species that are threats to humans in other countries. Wildlife and domestic animals as well as humans can act as hosts for ticks, which means the ticks feed on them for a blood meal.
Ticks can be found where wildlife or animal hosts are present. Many different types of animals act as hosts for different species of ticks: deer, raccoons, opossums, dogs, cats, rodents (such as squirrels, chipmunks, rats, and mice), birds, and even lizards. Wooded areas, parks, grassy meadows, and even empty lots where these animals pass through or are all areas where ticks can be transferred to humans. Sometimes pets with ticks on them can bring them inside human dwellings.