![]() The large groups will perform the same behavior if disturbed, so the pulsating mass of harvestmen may be an even greater deterrent to potential predators. When disturbed, a single harvestman typically pushes its body up and down in a slow, vibrating motion. Harvestmen often will aggregate into groups in which the legs seem to be twined together and the bodies close to each other. The twitching probably attracts attention of possible predators and allows the harvestman to escape. Repetitive pulses of the signal create the twitches. ![]() "Pacemakers" located in the first segment of the legs (called the femur) send signals that make the muscles in the broken leg tighten, but the leg relaxes between signals. The long legs of harvestmen are easily detached and will twitch for some time after removal. If they feed on the harvestman, they would be considered parasites, but they would be "phoretic" mites if they merely hang on to be transported to locations that might provide a good source of food. It is not known what those mites are doing. Small red mites often are found hanging onto the legs or bodies of harvestmen. For protection, harvestmen can produce defensive chemicals that taste and smell bad. They feed by searching over the ground or over plants for small insects, eggs, or dead material (either plant or animal). Venom produced by spiders helps them in their role as predators, but harvestmen do not need venom because they are scavengers. Harvestmen essentially have an oval body without the separation. ![]() The cephalothorax is the fused head and thorax regions, which is distinct from the abdomen. Spiders have two body segments (see image above). Many people see the similarity of form and think that the harvestman, perhaps better known as the granddaddy longlegs, is a kind of spider. Usually, the fear is most focused on one group of arachnids known as spiders, but the other members (scorpions, mites, ticks and harvestmen) are seldom viewed favorably by humans. ![]() The term "arachnid" refers to a group of animals that possess four pairs of legs, chelicerae (fang-like mouthparts) and appendages near the mouth called "pedipalps." The term "arachnophobia" refers to a fear of such animals. ![]()
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