How Do Ticks Feed?

Ticks are tiny eight-legged parasites that feed on the blood of mammals, birds and reptiles. They are divided into two main groups: hard ticks and soft ticks. A hard tick has a hard plate, or scutum, that covers its back and protects its body. A soft tick lacks a scutum and has wrinkly skin covering its body. All ticks rely on certain physiological and anatomical features to locate a host and suck its blood.

Finding a Host

• Ticks mostly live in wooded or grassy areas and move around by crawling rather than flying. When they crawl up a branch or blade of grass, they wait until a host passes by. The parasites find their food by sensing an animal's exhalation of carbon dioxide. The front legs of a tick can sense carbon dioxide as well as body heat, odor and movement. When perched on grass, a tick engages in the behavior of questing by waving its front legs in the air to detect a victim. As a host crosses a tick's path, the tick grabs onto the host using its legs.

Feeding

• Ticks are known to feed on birds, deer, mice, cattle, lizards, horses and humans. Once a tick latches onto a host, it moves beneath the animal's hair or fur and chooses a spot of skin on which to begin feeding. A tick inserts its center mouthpart, called a hypostome, into the skin of its host. The hypostome is barbed, and once the hypostome is inserted into the skin, it is hard for the host to remove it. A tick uses its hypostome to suck up the host's blood into its body. As it feeds on blood, a tick's body begins to engorge. Spit from the tick acts as an anesthetic, which prevents the host from feeling any pain. The spit also acts as an anticoagulant and keeps the host's blood flowing so the tick can feed.

After a Meal

• A tick travels everywhere its host does since it is latched onto the host's skin. It can continue to feed on the host's blood for days or weeks at a time. Once the tick is fully engorged and satiated, it loosens its mouthpart and drops off its victim. A female tick that finishes feeding lays eggs in plants or dead leaves. After laying eggs, soft ticks can move on to feed again and lay more eggs, while hard ticks die after laying eggs.

Carriers of Disease

• Ticks are dangerous to humans because they carry diseases. When a tick feeds on the blood of an animal infected with a disease, it can pass disease to its next host since bacteria and viruses survive in a tick's gut. Some diseases ticks spread to humans include Lyme disease, Rocky Mountain spotted fever and Tularemia. These diseases produce flu-like symptoms that consist of fevers, headaches, muscle aches, rashes, nausea and vomiting. If you experience any of these symptoms after bitten by a tick, seek medical treatment.