Species distinctions: Scorpion:
Body length: 12.0 cm ( 4.75 in)
Young: born during one to three week period, one after another
Diet: spiders, insects
Distinctive qualities: a venomous sting

Habits, physical and social structures:

Worldwide, there are several species of scorpion, all of which may be found in warm regions, of which a selected few may venture into more temperate areas, south or north from the rest. Overall, scorpions prefer hot places, even desert, where they are nocturnal, feed on spiders and insects and fight during the mating season. They are most noted for their poisonous sting, located at the back of the body, sharp and curved inwards. The sting is connected to a large gland at the base, where the venom may be observed. To sting its resisting or large prey, the scorpion bends its abdomen over its head and strikes violently with the sting, which may kill a small rodent in merely minutes as the poison is at least as toxic as that of a snake. Some species may be capable of killing of human with its poison.

Physics Application(s):

Seismic communication: Although the scorpion is best known for its sting, a lesser known fact is that the scorpion has the ability to locate prey by utilizing seismic vibrations. In 1970, it was displayed that scorpions could locate, with precision, minute disturbances within the sand 10.0 to 15.0 cm (3.9 to 5.9 in) and could also detect seismic vibrations up to 0.5 m (1.6 ft) away from their small body. Such results were unusual, as many organisms capable of detecting such vibrations are unable to precisely locate the origin of the seismic motions in a solid substrate such as sand. From this, it was derived the basitarsal compound slit sensilla (BCSS) must transduce the information in order for the scorpion to detect movement.

The BCSS are composed are many slit-shaped impressions found in the cuticle, variously arranged, above each of the eight tarsal joints, where a sensory nerve enervates each slit. The BCSS are ultra sensitive to vibrations and are able to respond to the footsteps of humans walking in the laboratory next door to the experiment lab, even while resting upon a "vibration free" table.

To expand on the concept, an audio speaker system was connected to a stimulator which would vary amplitude and frequency parameters independently. The result was the discovery that individual slits of the BCSS responded with variety mostly with amplitude and not frequency.

In 1998, experiments were completed in order to test the ability of scorpions to use seismic echolocation, where they could detect and use information from their own movements reverberating off objects near them. Scorpions were placed in a sensitive recording chamber which employed a piezoelectric crystal to detect the frequency of seismic waves which may have been created as the scorpion walked along the sand. The experiment would be able to provide a study of physical properties of scorpion seismic wave transmission across sand, including range, speed, and the affect of local objects on the characteristics of the waves. The scorpions were dropped individually into the center of a circular arena where one quadrant was removed. The movements of the individuals were measured in infrared wavelengths and other controls to eliminate visual and chemical cues, comparing the open quadrant and magnetic north. The trials were performed under two sets of conditions: first, the arena was in contact with sand, and second, the arena was suspended above the sand: if the scorpions depended on seismic vibrations for orientation, they should be biased toward or away from the open quadrant in trials where the area was in contact with sand. Results yielded included random movements in relation to magnetic north, however movements made in relation to the open quadrant were found to be non-random in both sets of conditions. Such results put forth proof that sand scorpions are capable of detecting objects without visual or chemical cues, even if the object is not in contact with the sand surface, which then suggests that other than using the BCSS, the trichobothria is involved (fine hairs with constricted based that may move with even the slightest current of air).

Anemaw [Animal Electromagnetism and Waves] © Elizabeth Gerrow 2002 .