Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved venom apparatus, such as fangs or a stinger, in a process called envenomation. Venom is often distinguished from poison, which is a toxin that is passively delivered by being ingested, inhaled, or absorbed through the skin, and toxungen, which is actively transferred to the external surface of another animal via a physical delivery mechanism.
A cnidocyte is an explosive cell containing one large secretory organelle called a cnidocyst that can deliver a sting to other organisms. The presence of this cell defines the phylum Cnidaria. Cnidae are used to capture prey and as a defense against predators. A cnidocyte fires a structure that contains a toxin within the cnidocyst; this is responsible for the stings delivered by a cnidarian. Cnidocytes are single-use cells that need to be continuously replaced.
Centipedes are predatory arthropods belonging to the class Chilopoda of the subphylum Myriapoda, an arthropod group which includes millipedes and other multi-legged animals. Centipedes are elongated segmented (metameric) creatures with one pair of legs per body segment. All centipedes are venomous and can inflict painful stings, injecting their venom through pincer-like appendages known as forcipules or toxicognaths, which are actually modified legs instead of fangs. Despite the name, no centipede has exactly 100 legs; the number of pairs of legs is an odd number that ranges from 15 pairs to 191 pairs.
While observers can easily confuse common wasps and bees at a distance or without close observation, there are many different characteristics of large bees and wasps that can be used to identify them.
Hornets are the largest of the eusocial wasps, and are similar in appearance to yellowjackets, their close relatives. Some species can reach up to 5.5 cm (2.2 in) in length. They are distinguished from other vespine wasps by the relatively large top margin of the head. Worldwide, 22 species of Vespa are recognized. Most species only occur in the tropics of Asia, though the European hornet is widely distributed throughout Europe, Russia, North America, and north-eastern Asia. Wasps native to North America in the genus Dolichovespula are commonly referred to as hornets, but all of them are actually yellowjackets.
The Mutillidae are a family of more than 7,000 species of wasps whose wingless females resemble large, hairy ants. Their common name velvet ant refers to their resemblance to an ant, and their dense pile of hair, which most often is bright scarlet or orange, but may also be black, white, silver, or gold. Their bright colors serve as aposematic signals. They are known for their extremely painful stings,, and has resulted in the common name "cow killer" or "cow ant" being applied to the species Dasymutilla occidentalis. However, mutillids are not aggressive and sting only in defense. In addition, the actual toxicity of their venom is much lower than that of honey bees or harvester ants. Unlike true ants, they are solitary, and lack complex social systems.
Urticating hairs or urticating bristles are one of the primary defense mechanisms used by numerous plants, almost all New World tarantulas, and various lepidopteran caterpillars. Urtica is Latin for "nettle", and bristles that urticate are characteristic of this type of plant, and many other plants in several families. This term also refers to certain types of barbed bristles that cover the dorsal and posterior surface of a tarantula's or caterpillar's abdomen. Many tarantula species eject bristles from their abdomens, directing them toward potential attackers. These bristles can embed themselves in the other animal's skin or eyes, causing physical irritation, usually to great discomfort. The term "hairs" is technically a misnomer, as only mammals possess true hairs. The scientific term for plant hairs is trichomes.
Envenomation is the process by which venom is injected by the bite or sting of a venomous animal.
A bee sting is the wound and pain caused by the stinger of a female bee puncturing skin. Bee stings differ from insect bites, with the venom of stinging insects having considerable chemical variation. The reaction of a person to a bee sting may vary according to the bee species. While bee stinger venom is slightly acidic and causes only mild pain in most people, allergic reactions may occur in people with allergies to venom components.
Venomous fish are species of fish which produce strong mixtures of toxins harmful to humans which they deliberately deliver by means of a bite, sting, or stab, resulting in an envenomation. As a contrast, poisonous fish also produce a strong toxin, but they do not bite, sting, or stab to deliver the toxin, instead being poisonous to eat because the human digestive system does not destroy the toxin they contain in their bodies. Venomous fish do not necessarily cause poisoning if they are eaten, as the digestive system often destroys the venom.
In a zoological context, spines are hard, needle-like anatomical structures found in both vertebrate and invertebrate species. The spines of most spiny mammals are modified hairs, with a spongy center covered in a thick, hard layer of keratin and a sharp, sometimes barbed tip.
A centipede bite is an injury resulting from the action of a centipede's forcipules, stinger-like appendages that pierce the skin and inject venom into the wound. Such a wound is not strictly speaking a bite, as the forcipules are a modified first pair of legs rather than true mouthparts. Clinically, the wound is viewed as a cutaneous condition characterized by paired hemorrhagic marks that form a chevron shape caused by the paired forcipules.
Ant venom is any of, or a mixture of, irritants and toxins inflicted by ants. Most ants spray or inject a venom, the main constituent of which is formic acid only in the case of subfamily Formicinae.
A scorpion sting is an injury caused by the stinger of a scorpion resulting in the medical condition known as scorpionism, which may vary in severity. The anatomical part of the scorpion that delivers the sting is called a "telson". In typical cases, scorpion stings usually result in pain, paresthesia, and variable swelling. In serious cases, scorpion stings may involve the envenomation of humans by toxic scorpions, which may result in extreme pain, serious illness, or even death depending on the toxicity of the venom.
A stingray injury is caused by the venomous tail spines, stingers or dermal denticles of rays in the order Myliobatiformes, most significantly those belonging to the families Dasyatidae, Urotrygonidae, Urolophidae, and Potamotrygonidae. Stingrays generally do not attack aggressively or even actively defend themselves. When threatened, their primary reaction is to swim away. However, when attacked by predators or stepped on, the stinger in their tail is whipped up. This is normally ineffective against sharks, their main predator.
Many species of arthropods can bite or sting human beings. These bites and stings generally occur as a defense mechanism or during normal arthropod feeding. While most cases cause self-limited irritation, medically relevant complications include envenomation, allergic reactions, and transmission of vector-borne diseases.
Grasshopper mice are rodents of the genus Onychomys, occurring in North America. They feed on insects and other arthropods.
Vespula squamosa, or the southern yellowjacket, is a social wasp. This species can be identified by its distinctive black and yellow patterning and orange queen. This species is typically found in eastern North America, and its territory extends as far south as Central America. Within these territories, they create enormous, multiple-comb nests. The colonies may be either annual or perennial depending on the climate, and in many perennial nests, polygyny takes place. In addition, this species uses pheromones both as a sexual attractant and an alarm signal. This species feeds on insects and animal carcasses; it does not produce honey. V. squamosa, a social insect, has developed a parasitic relationship with the species V. vidua and V. maculifrons. Due to their painful, venomous stings, the species is considered a pest.
Onychocerus albitarsis is a relatively rare species of beetle in the family Cerambycidae from the Amazon and Atlantic forest regions in Brazil, Bolivia, Paraguay and southern Peru. It is remarkable for being the only known beetle that has a venomous sting and the only known arthropod that stings with its antennae. Each antenna ends in a stinger that has evolved to resemble a scorpion's tail and it is connected to a venom gland. The sting was already reported in 1884 but researchers thought the pain only was caused by the sharpness of the antennae, as also known from some other beetles. It was only confirmed in 2005 that it is venomous when a biologist was stung, comparing it to a bee sting, and subsequently studied it in detail. In the first of two other cases where the identity of the stinging insect was confirmed to be this beetle, a woman experienced significant pain directly after the incident, and redness and itching at the sting site that lasted for a week. In the other case a man experienced moderate pain directly after being stung and redness that only lasted for an hour. The other species in the genus Onychocerus appear to not be venomous since they lack the structures inside the antennae that are associated with the venom apparatus of Onychocerus albitarsis.
