Another group of Hymenoptera occasionally causes much harm in fir plantations, namely, the Siricidae or wood-wasps, whose larvae burrow into the trunks of the trees and thus kill them.
If an aperture for ingress and egress, for purposes of feeding, were left in the wall of such a chamber, there would arise in a rudimentary form what is known as the tubular nest or web; and the next important step was possibly the adoption of such a nest as a permanent abode for the spider., Some spiders, like the Drassidae and Salticidae, have not advanced beyond this stage in architectural industry; but next to the cocoon this simple tubular retreat - whether spun in a crevice or burrow or simply attached to the lower side of a stone - is the most constant feature to be observed in the spinning habits of spiders.
In both there are species which form no nest or burrow, others which construct a simple silk-lined tunnel in the soil, and others which close the aperture of the burrow with a hinged door; while both share the habit of lining the burrow with silk to prevent the infall of loose sand or mould; and the species which make an open burrow close the aperture with a sheet of silk in the winter during hibernation and open it again in the spring.
As a rule terrestrial spiders guard the cocoon in the permanent burrow, as in the trap-door spiders, or in the silken retreat which acts as a temporary nursery, as in the Salticidae.
They burrow among tall grass.
The male does not burrow, but wanders freely on the surface of the skin.
Other caterpillars, "budworms" (Heliothis, spp.), attack the buds or burrow into the seed-pods.
It lives in a burrow, generally excavated by itself; but when pursued, seeks safety in flight, rather than by a retreat to its hole.
These tail-shielded snakes, of which about 40 species are known, are viviparous and burrow in the ground, preferring damp mountainforests.
Yet it may be thought that the usual instinct of the " diggingwasps " to capture and store up food in an underground burrow for the benefit of offspring which they will never see is even more surprising.
On retiring for the winter the hamster closes the various entrances to its burrow, and becomes torpid during the coldest period.
All the skinks seem to be viviparous, and they prefer dry, sandy ground, in which they burrow and move quickly about in search of their animal food.
Here in the spring the half-dozen or more coyote pups are brought forth; and it is said that at this season the old ones systematically drive any large game they may be chasing as near to their burrow, where the young coyotes are waiting to be fed, as possible before killing it, in order to save the labour of dragging it any great distance.
It is nowhere abundant, but is found over the northern parts of Europe and Asia, and is a quiet, inoffensive animal, nocturnal and solitary in its habits, sleeping by day in its burrow, and issuing forth at night to feed on roots, beech-mast, fruits, the eggs of birds, small quadrupeds, frogs and insects.
Some are perforating algae and burrow into the substance of molluscan shells, in company with certain Green and Blue-green Algae.
During the daytime the hillock at the entrance to the burrow is frequently occupied by one or more members of the family, which at the approach of strangers sit up on their hind-legs in order to get a better view.
If alarmed they utter a shrill loud whistle, and rush down the burrow, but reappear after a few minutes to see if the danger is past.
Old Johnson, in his "Wonder-Working Providence," speaking of the first settlers of this town, with whom he was contemporary, tells us that "they burrow themselves in the earth for their first shelter under some hillside, and, casting the soil aloft upon timber, they make a smoky fire against the earth, at the highest side."
I dug my cellar in the side of a hill sloping to the south, where a woodchuck had formerly dug his burrow, down through sumach and blackberry roots, and the lowest stain of vegetation, six feet square by seven deep, to a fine sand where potatoes would not freeze in any winter.
My instinct tells me that my head is an organ for burrowing, as some creatures use their snout and fore paws, and with it I would mine and burrow my way through these hills.