Curiously enough, if disturbed, they entirely decline to burrow unless it be the proper season for that operation, but remain inert and helpless on the surface till they die. If, however, a tunnel is provided for them, they enter it at once and adapt it to their needs.
The legs take no part in the burrowing process, which is entirely carried out by the jaws. With infinite labour small particles of earth are dislodged and carried by the mandibles to be dropped at a considerable distance from the nest.
The parapet round the mouth of the tube is in nature usually quite a small erection, but this seems to be due to the fact that only a small amount of suitable material is available in the immediate neighbourhood, and the spiders will not go far afield. In captivity, when abundance of material was supplied, they attained a height of two inches. Small stones, sticks, and strands of wool cut into lengths of one inch and of various colours were placed within reach, and all were used in building the parapet. Comparatively huge pebbles were rolled up for a foundation, and fragments of earth and pieces of wool entirely irrespective of colour were bound together by irregular spinning work.
On sunny days the spiders would crouch behind the parapet with their eyes above its level. To distant insects they paid no attention, but if one approached within leaping distance, it was pounced upon with unfailing accuracy.
In due season the captives laid their eggs and enclosed them in the regulation cocoon which they attached to their spinnerets, never parting from them thenceforward, though considerably hampered by them in their movements up and down the tube. But a very remarkable change now took place in their behaviour at the mouth of the tunnel. In sunny weather, instead of remaining, as Fabre puts it, “accoudé” on the parapet, they reversed their position, raised their egg-cocoons with their hind legs, and slowly and deliberately turned them about, so that every part in succession should be exposed to the sun’s rays.
We now come to a remarkable habit possessed by all the Lycosidae. When the young are ready to leave the cocoon they find an exit at the thinner equatorial seam, and proceed immediately to climb on to the back of the mother, clinging firmly to her covering of hairs. If a wanderer, she carries them thus on all her expeditions; if a stay-at-home, they accompany her up and down her tube. They are often dislodged—indeed, when alarmed, they scatter for the moment, but when the peril has passed they immediately swarm up the maternal legs to their former position.
Now in the case of the tarantula, it is seven months before they are able to fend for themselves. Meanwhile they eat nothing, and look on with indifference while their mother feeds. She not only carries them willingly, but exhibits solicitude when deprived of them, but she shows no discrimination as to her own offspring, and is quite content with those of another spider. The young, when brushed off, climb the legs of the nearest female, and a spider may thus be laden with thrice her proper load without any protest. They form a layer two or three deep, and can then only find room by covering the whole of her back. They nevertheless take care not to obscure her vision by covering her eyes.
Two mother tarantulas, each with her young on her back, came into contact, and a battle à outrance took place. One was slain, but the double brood, scattered by the conflict, on its cessation climbed on to the back of the victor, and remained calmly in position while she proceeded to dine in leisurely fashion on the vanquished!
In March, seven months after hatching, the young were ready to start life for themselves. Their first action was to climb to the highest points attainable, whence they set sail in the manner already described, and were borne gently away in the air.
We can hardly leave the tarantula without saying something on the vexed question of spider venom. All over the world there are certain particular spiders whose bite is especially feared. Among them are the “Tarantula” and the “Malmignate” of southern Europe, the “Vancoho” of Madagascar, the “Katipo” of New Zealand, and the “Queue rouge” of the West Indies. Quite an extensive literature has arisen around the subject but its perusal leaves one not much wiser than one was before. Circumstantial accounts of deaths from the bite of a spider are countered by the assertions of experimenters that they have allowed themselves to be bitten repeatedly by the same species without suffering any inconvenience. There is at all events some basis for the popular view in the fact that all spiders possess a poison gland which is analogous to that of the snake inasmuch as it opens near the tip of the fang which is plunged into the animal attacked. In the case of the large, powerful spiders of the family Mygalidae, and perhaps in the tarantulas the effects of the bite on higher animals are not negligible, and clearly exceed the results of a mere puncture. A young sparrow and a mole bitten by Fabre’s tarantula in spots by no means vital died within a few hours. But it is a very remarkable fact that many of the most dreaded spiders are neither large nor powerful. The “Malmignate,” the “Vancoho,” the “Katipo,” and the “Queue rouge” are all members of the comparatively weak-jawed Theridiidae, and their only striking characteristic is vivid coloration, all being marked with red spots. It is probable that their deadly powers are almost entirely fabulous; and that they have been singled out as particularly dangerous merely because of their conspicuous appearance.