All are viviparous, and the females carry the newly-hatched young on their backs. They are predaceous, feeding for the most part on insects and spiders. These are seized by the chelate pedipalps, and, if small, are simply picked to pieces by the chelicerae and devoured, but if large the tail-sting is brought into play and the victim quickly paralysed. The process of eating is a slow one, and a Cape scorpion in captivity took two hours to devour a cockroach.
In walking, scorpions carry their pedipalps horizontally in front, using them partly as feelers and partly as raptorial organs. As regards the body the attitude varies considerably. In some cases (Parabuthus, Prionurus, etc.) it is raised high upon the legs, and the “tail” or metasoma is curved forward over the back, but in others (Euscorpius) the body is held low, and the “tail” is dragged along behind, the end only being slightly curled. In the daytime they hide away under wood or stone, or in pits which they dig in the sand. Parabuthus capensis was observed to dig a shallow pit by means of its second and third ambulatory legs, resting on its first and fourth legs aided by the chelae and the metasoma. Those that hide under wood are usually found clinging to their shelter ventral side uppermost. In captivity the creatures, though supplied with water, were never observed to drink; indeed, they are characteristic inhabitants of arid steppes and parched wastes. Like most Arachnids they can endure prolonged abstinence from food.
The only sense well developed seems to be that of touch. Notwithstanding the possession of several eyes their sight is poor. A moving object within the range of a few inches is certainly perceived, but it has to be touched before its nature is recognised. Some writers have attributed to scorpions a keen sense of hearing, and so-called “auditory hairs” are described on the tibia of the pedipalp, but Pocock came to the conclusion that Parabuthus capensis and Euscorpius carpathicus were entirely deaf, and Lankester could obtain no indication of auditory powers in the case of Prionurus. The sense of touch is extremely delicate, and seems to reside in the hairs with which the body and appendages are more or less thickly clothed. The pectines are special tactile organs. That they are in some way related to sex seems probable from the fact that they are larger in the male and sometimes curiously modified in the female, but they appear to be of use also in determining the nature of the ground traversed by the animal, being long in such species as raise the body high on the legs, and short in those that adopt a more grovelling posture. Pocock noticed that a scorpion which had walked over a portion of a cockroach far enough for the pectines to come in contact with it immediately backed and ate it.
Fig. [167].—Buthus occitanus in the mating period. (After Fabre.)
As is the case with most poisonous animals, their ferocity has been much exaggerated; they never sting unless molested, and their chief anxiety is to slink off unobserved. The fables that they kill their young, and that when hard pressed they commit suicide by stinging themselves to death, perhaps hardly deserve serious consideration. The latter accusation is disproved by the fact that a scorpion’s poison has no effect upon itself, or even upon a closely allied species. Some writers think that in the frantic waving of the “tail,” which is generally induced by strong excitement, a scorpion may sometimes inadvertently wound itself with the sharp point of its telson.
Fabre gives a fascinating account of the habits of Buthus occitanus, which occurs in the south of France. He found these scorpions plentifully in arid, stony spots exposed to the sun. They were always solitary, and if two were found under the same stone, one was engaged in eating the other. Their sight is so poor that they do not recognise each other without absolute contact.
Fabre established colonies in his garden and study, providing them with suitable soil and sheltering stones. They dug holes by reducing the earth to powder by means of the three anterior pairs of legs—never using their pedipalpi in the operation—and sweeping away the débris with the tail. From October to March they ate nothing, rejecting all food offered to them, though always awake and ready to resent disturbance. In April appetite seemed to awaken, though a very trifling amount of food seemed to suffice. At that time, too, they began to wander, and apparently without any intention of returning, and they continued daily to escape from the garden enclosure until the most stringent measures were taken to keep them in. Not till they were surrounded by glass and the framework of their cages covered with varnished paper were their attempts to climb out of their prison frustrated. Fabre came to the conclusion that they took at least five years to attain their full size.
Fig. [168].—The “promenade à deux” of Buthus occitanus. (After Fabre.)