Parasites need a host. If a host tries to get rid of the parasite or kill it, then the parasite either has to leave the body or die.
<em>Structure and Function of ArthropodsArthropods range in length from about 1 millimeter to 4 meters (about 13 feet). They have a segmented body with a hard exoskeleton. They also have jointed appendages. The body segments are the head, thorax, and abdomen. </em><span><em> In some arthropods, the head and thorax are joined together as a cephalothorax.</em></span>
Water evaporates from the ocean and land surfaces, is held temporarily as vapour in the atmosphere, and falls back to Earth's surface as precipitation. ... Water that infiltrates Earth's surface becomes groundwater, slowly seeping downward into extensive layers of porous soil and rock called aquifers.
