The tick is a parasite, found almost everywhere in the world, that feeds on the blood of a wide range of vertebrates. The amount of blood lost is generally insignificant for the host, whether human or an animal. What makes the tick dangerous however, is its role as a carrier of pathogens that can cause serious diseases for humans and animals.
Ticks are arachnids
In biological terms, ticks are classified as arachnids. Like a spider, the adult tick also has eight legs, but is more physically similar to mites because their bodies aren’t segmented, and the cephalothorax and abdomen are combined into one body region. The tick is a highly specialized creature, with a body and behaviors that are exceptionally well-adapted to their environment. As a parasite, it relies on other creatures to survive, feeding on their blood– similar to the mosquito.
Compared to mosquitoes, however, ticks need a lot more blood. In extreme cases they remain attached to their host (human or animal) for up to 15 days, feeding on their blood. That is why they tend to seek out a soft, warm spot on their victim, such as the armpits or genital area, to firmly latch onto. While attached, ticks can even withstand the occasional scratching or rubbing without being harmed.
Ticks in Germany
The castor bean tick (Ixodes ricinus) is the most widely distributed type of tick in Europe and the one that most often bites humans. If the tick is infected with pathogens, an otherwise harmless tick bite can pose a serious health risk. Even in Germany these health risks are possible, as pathogens are transferred from the tick's salivary gland and intestines directly into the bloodstream of the host via the tick's stinger. The right precautions are therefore vital.
The anatomy of a tick
The stinging and sucking organs for blood intake are located on the "head" of a tick. The front pair of legs contain the sensory organs and strong claws, with which ticks hold onto their victims' skin. A breathing hole is located behind the last pair of legs and the genitals are on the lower section of the abdomen.
Hooked on and glued down
The stinger of a tick has a long row of tiny barbs arranged symmetrically along it, helping ticks to tightly attach themselves to the host. Some kinds of ticks have a shorter stinger, so they also produce a “glue” to firmly adhere themselves to their host.
How big do ticks get?
Blood makes a tick grow in size. It sucks blood directly into its intestinal tract. The tick's weight increases significantly during the blood feeding process. As its intestine is stretchable and consists of many appendages, a fully engorged tick can weigh as much as 200 times its initial weight.
How long do ticks live?
A tick can survive a very long time on just a single feed. Under test conditions in the lab, ticks that have already had a blood meal can live up to ten years without additional feeding. In the wild, the local castor bean ticks can live between three and five years on a single feeding.