It is nocturnal in its habits, and very seldom is seen during the hours of daylight, so that it cannot be captured by chase. It is not gregarious, so that it cannot be taken in great numbers, as is the case with certain wild animals which have been thought to be the Tachash of Scripture. It is not a careless animal, so that it cannot be captured or killed without the exercise of considerable ingenuity, and the expenditure of much time and trouble. It is one of the burrowing animals, digging for itself a deep subterranean home, and always ready whenever it is alarmed to escape into the dark recesses of its dwelling, from which it can scarcely be dislodged. It is not a large animal, so that a considerable number of skins would be required in order to make a covering which should overlap a structure forty-five feet in length and fifteen in breadth. Were it a solitary animal, there might be a difficulty in procuring a sufficient number of skins. But it is partly gregarious in its habits, living together in small families, seven or eight being sometimes found to inhabit a single dwelling-place. It is, therefore, sufficiently rare to make its skin valuable, and sufficiently plentiful to furnish the requisite number of skins. All these facts tend to show that the cost of such a covering must have been very great, even though it was the outermost, and, consequently, the least valuable of the four. It has been suggested that these skins were only used to lay over the lines where the different sets of coverings overlapped each other, and that, in consequence, they need not have been very numerous. But we find that these same skins, which were evidently those which formed the external roof, were used, when the Tabernacle was taken down, for the purpose of forming distinct coverings for the ark of the testimony, the table of shewbread, the seven-branched candlestick, the golden altar, the various vessels used in the ministrations, and lastly, the altar of sacrifice itself. Thus, when we recollect the dimensions of the ark, the table, the candlestick, and the two altars, we shall see that, in order to make separate covers for them, a quantity of material would be used which would be amply sufficient to cover the whole roof of the Tabernacle, even if it had, as was most probably the case, a ridged, and not a flat roof.