This family is named from a fancied resemblance of the larvae to the celebrated Egyptian sphinx. The perfect insects have very thick bodies, generally tapering toward the tail, and their wings are rather narrow in proportion to the length, but are exceedingly powerful, and the flight is, with one or two exceptions, very rapid. The antennae terminate in a small and thin hook. Most of these insects fly at dusk, but a few delight in the brightness and heat of the midday sun. In either case the velocity of their flight is generally so great that it is a difficult matter to follow them with the eye, and a still more difficult matter to secure the insects in the net; consequently, the best way to study them is to search out the larvae on their food plants, and rear them till they attain their perfect form. The larvae of the _Sphingidae_ are large and smooth, and most of them have a horn projecting from the top of the last segment but one. They all undergo their metamorphoses under the surface of the ground. _The Death's-Head Hawk_ (_Acherontia Atropos_) Our first example of the Sphinges is the beautiful Death's-Head Hawk Moth--an insect that often attains a breadth of five inches from tip to tip when the wings are fully expanded. Its popular title has been applied on account of the peculiar markings of the thorax, which are said to resemble a human skull; and this feature has certainly some connection with the superstitious beliefs of ignorant country folk concerning this moth. But this characteristic is probably not the only one that has caused the creature to be regarded with superstitious alarm. Both its superior dimensions and nocturnal habits serve to intensify the unfounded fear; but, what is particularly striking and unique about it is its power of uttering a squeaking sound, which it does when disturbed. Even the earlier stages of the insect possess this strange power. The caterpillar makes a peculiar snapping noise when irritated, and the chrysalis has been observed to squeak shortly before the emergence of the perfect form. The fore wings of this moth are of a very rich dark brown, beautifully mottled with lighter tawny shades, and with a small but conspicuous yellow dot near the centre. The hind wings are yellow, with a black band and margin; and the body is yellow, with six broad black bands, and six large blue spots down the middle. [Illustration: FIG. 97.--THE DEATH'S-HEAD HAWK MOTH.] The moth is rather widely distributed, and even common in some parts, but is not nearly so often met with as the larva. It is on the wing during August and September.