The Pacific Coast tick is also common in the park. Both male and female Pacific Coast ticks have some gray on their bodies, but the female's gray is confined to the shield portion of her back. The soft-bodied pajahuello tick is less common in the park. Although it's not known to carry human diseases, some people are allergic to its bite and can develop a severe reaction, with swelling, redness, and pain that take several months to disappear. Several much less common species of ticks in the park attach to hosts that humans don't often come in contact with, and they don't seem to have developed a taste for human blood.
All ticks know when prey is near.
They use sense organs to detect animal scent, carbon dioxide, and heat. The adult western black-legged and Pacific Coast ticks are usually found at the end of grass stems or other vegetation, often along trails. They can also be found in brush. Younger stages crawl onto prey from the ground and low vegetation. The adult ticks wait, with their front legs outstretched, and when an animal brushes against the vegetation, the tick grabs on.