TRAP-DOOR SPIDER.
NEST OF TRAP-DOOR SPIDER.
TRAP-DOOR OPENING BY A LEVER.
As might be expected, there are varieties in the shape and size of these nests. Some specimens found in the island of Zante had the silken layers of the lid extended into a sort of handle or lever just above the hinge, on pressing which in ever so slight a degree the trap-door opened. From this it would appear that the entrance to such a nest could be effected as easily by the enemies of the spider as by the spider itself: this, however, is not the case; for repeated observation has shown that the spider keeps guard at the entrance, and actually holds the door with her fore feet and palpi, while the hinder feet are extended down the side of the nest, and the mandibles are thrust into the opposite side near the door. By this means the insect gets such power as to resist with considerable force the opening of the door. If it be asked how this is known, we are able to refer to the experiments of careful observers, who extracted a number of nests from the ground, and opening them at the lower end, looked up, and saw the spider so occupied. A sectional view of the nest will show that the curved form of the cover, and the shape of the side walls, must favour this method of keeping the door shut. In some cases, small hollows were formed round the interior edge of the lid, into which the spider thrust its feet when keeping guard. It is a curious fact, that when several of these spiders enclosed in their nests were kept as a matter of curiosity in a box of earth, and the doors frequently opened to examine their proceedings, one or two of them, as if wearied at these repeated interruptions, effectually closed their doors by weaving a piece of silken tapestry, which was spread over the interior of the opening, and rounded like the inside of a thimble. This was so strongly attached to the door and to the side walls, that no opening could be made without destroying the nest.
SECTION OF NEST.
It was long a matter of surprise to the observer to find, that in the case of some nests, and not of others, there was a trap-door at the bottom as well as at the top of the nest: this was at last explained by the following fact. A spider’s nest, which was accidentally broken off in being extracted from the ground, was purposely restored to the earth in a reversed position, with the trap-door downwards, and the broken and exposed part level with the surface. The spider immediately set to work to make a new door over the broken part, and finished it with as much completeness as the other. Doubtless, then, those nests which were provided with two doors were such as had been upset and broken. This is the more likely because in Zante, where such nests were found, the earth is annually dug up round the roots of the olive tree, a favourite nesting place of these trap-door spiders.
