The Crotalinae, commonly known as pit vipers, crotaline snakes, or pit adders, are a subfamily of venomous vipers found in Asia and the Americas. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on either side of the head.
What makes this group unique is that they all share a common characteristic: a deep pit, or fossa, in the loreal area between the eye and the nostril on either side of the head. These loreal pits are the external openings to a pair of extremely sensitive infrared detecting organs, which in effect give the snakes a sixth sense that helps them to find and perhaps even judge the size of the small warm-blooded prey on which they feed.
The pit organ is complex in structure and is similar to the thermoreceptive labial pits found in boas and pythons. It is deep and located in a maxillary cavity. The membrane is like an eardrum that divides the pit into two sections of unequal size, with the larger of the two facing forwards and exposed to the environment. The two sections are connected via a narrow tube, or duct, that can be opened or closed by a group of surrounding muscles. By controlling this tube the snake can balance the air pressure on either side of the membrane. The membrane has many nerve endings packed with mitochondria. Succinic dehydrogenase, lactic dehydrogenase, adenosine triphosphate, monoamine oxidase, generalized esterases and acetylcholine esterase have also been found in it. When prey comes into range, infrared radiation falling onto the membrane allows the snake to determine its direction. Having one of these organs on either side of the head produces a stereo effect that indicates distance as well as direction. Experiments have shown that, when deprived of their senses of sight and smell, these snakes can strike accurately at moving objects that are less than 0.2°C warmer than the background. The paired pit organs would seem to provide the snake with thermal rangefinder capabilities. It is clear that these organs are of great value to a predator that hunts at night as well as well as for avoiding the snake’s own predators.
Among vipers, these snakes are also unique in that they have a specialized muscle, called the muscularis pterigoidius glandulae, between the venom gland and the head of the ectopterygoid. Contraction of this muscle, together with that of the m. compressor glandulae, forces venom out of the gland.
Whipscorpion, any of a group of arachnids characterized by a whip-like tail and the ability to spray acetic acid at attackers. They are also called vinegaroons, because of their vinegar-like defensive spray, and uropygids, after their order. Whipscorpions live under leaf litter or rocks and hunt small arthropods and other invertebrates. They range throughout tropical and subtropical Asia and the Americas. There are about 100 species.
The front section of the body, or cephalothorax, of the whipscorpion is covered by a carapace, or shell-like case . The whipscorpion has one pair of eyes toward the front of the cephalothorax and three or four pairs to the side. Its large chelicerae, or jaws, resemble the claws of a crab and are composed of several hinged segments. The chelicerae grasp and shred small prey and then transfer it to the pedipalps, or leg-like mouthparts. The foremost pair of walking legs is longer and more slender than the other three, and these legs are used like antennae to detect prey and to explore the environment ahead.
Whipscorpions breathe through two pairs of layered lungs, called book lungs, on the abdomen. The whiplike telson, or tail, is sensitive to light, which the whipscorpion avoids. At the base of its telson, the whipscorpion has two glands that are capable of spraying acid at predators. The acid is mostly acetic, which has a vinegar smell, and is accompanied by a small amount of caprylic acid, which helps the acetic acid pass through the exoskeleton, or outer skin, of other arthropods. The acids can also burn human skin and eyes, although the amount ejected by the whipscorpion is not dangerous.
The longhorn beetles (Cerambycidae; also known as long-horned beetles or longicorns) are a cosmopolitan family of beetles, typically characterized by extremely long antennae, which are often as long as or longer than the beetle's body. In various members of the family, however, the antennae are quite short (e.g., Neandra brunnea, figured below) and such species can be difficult to distinguish from related beetle families such as Chrysomelidae. The family is large, with over 20,000 species described, slightly more than half from the Eastern Hemisphere. Several are serious pests, with the larvae boring into wood, where they can cause extensive damage to either living trees or untreated lumber (or, occasionally, to wood in buildings; the old-house borer, Hylotrupes bajulus, being a particular problem indoors). A number of species mimic ants, bees, and wasps, though a majority of species are cryptically colored. The rare titan beetle (Titanus giganteus) from northeastern South America is often considered the largest (though not the heaviest, and not the longest including legs) insect, with a maximum known body length of just over 16.7 centimetres (6.6 in).