Not every tick bite yields disease, since not every tick carries pathogens or bites long enough to transmit them. Still, most reported cases of vector-borne disease (including mosquitoes) come from ticks, which can carry pathogens with terrible consequences.

Lyme disease is the most common tick-borne disease in the U.S., estimated to affect more than 470,000 people each year.

But ticks can actually expose people in the U.S. to more than a dozen different disease-causing agents," including toxins, allergens, bacteria, parasites and viruses.