[85] Oestrus ovis in naso sive sinu frontis animalium rumenantium. Linn.
The gnat, the ephemera, the phryganea, the libellula, hover over the water all day to drop their eggs, which are hatched in the water, and continue there all the time they are in the larva form. The mass formed by the gnat resembles a little vessel set afloat by the insect; each egg is in the form of a keel, these are curiously connected together. The gnat lays but one egg at a time, which she deposits on the water in a very ingenious and simple manner; she stretches her legs out, and crosses them, thus forming an angle to receive and hold the first egg; a second egg is soon placed next the first; then a third, and so on, till the base is capable of supporting itself; these, as they come to maturity, sink deeper. The spawn of this insect is sometimes above an inch long, and one-eighth of an inch in diameter, and tied by a little stem or stalk to some stick or stone. Sometimes they are laid in a single, sometimes in a double spiral line; sometimes transversely. Many moths cover their offspring with a thick bed of hair, which they gather from their own body; while others cover them with a glutinous composition, which, when hard, protects them from moisture, rain, and cold. The gall-flies, it has been observed, know how to open the nerves of the leaves, to deposit thus their eggs in a place which afterwards serves them for a lodging and a magazine of food. The solitary bees and wasps prepare an habitation for their little ones in the earth, placing there a proper quantity of food for them, when they proceed from the egg. The voracious and cruel spider is attentive and careful of its eggs; the wolf spider carries them on its back in a little bag formed of its silk, it cannot be separated from them but by violence, and exhibits the most marked signs of uneasiness when deprived of them: a circumstance the more remarkable, as they love to destroy each other, and even carry on their courtships with a diffidence and caution unknown in any other species of animals. The history of bees and wasps, and their care and attention to their offspring, is so well known, that I may with propriety pass it over here, and proceed just to notice the industrious ant, whose paternal affection and care is not so well known. They are not satisfied with placing their eggs in situations made on purpose, and to raise or rear them till they come to the nymph or pupa state, but they even extend their care to the pupæ themselves, removing them from their nest to the surface of the earth, whenever the weather is fine, that they may receive the benignant influence of the sun, carrying them back again as soon as the air begins to grow cold. If any accident disturb their nest, and disperse the pupæ, they manifest the greatest signs of distress, seeking those which are lost and scattered, placing them in some sheltered place while they repair the nest, when they again transport them to it.[86] Many other curious particulars might be related relative to this industrious insect; as their uniting together in scooping out earth, the conveyance of materials for the construction of their nests, and the curious structure of the nest itself, which, though it appears piled up at random, will be found, on stricter examination, to be a work of art and design, with other circumstances which are too long to be enumerated here.