The vast majority of victims fully recover without significant lasting problems (sequelae). Death from latrodectism is reported as high as 5% to as low as 0.2%. In the United States, where antivenom is rarely used, there have been no deaths reported for decades.

Despite frequent reference to youth and old age being a predisposing factor it has been demonstrated that young children appear to be at lowest risk for a serious bite, perhaps owing to the rapid use of antivenom. Bite victims who are very young, old, hypotensive, pregnant or who have existing heart problems are reported to be the most likely to suffer complications. However, due to the low incidence of complications these generalizations simply refer to special complications (see Special circumstances).

Efforts to prevent bites include clearing clutter and the use of pesticides.

OSHA recommends that workers take following measures to prevent spider bite:

- Wear a long-sleeved shirt, hat, gloves, and boots when handling boxes, firewood, lumber, rocks, etc.

- Inspect and shake out clothing and shoes before getting dressed.

- Use insect repellents, such as DEET or Picaridin, on clothing and footwear.

Spiders do not feed on humans and typically bites occur as a defense mechanism. This can occur from unintentional contact or trapping of the spider. Most spiders have fangs too small to penetrate human skin. Most bites by species large enough for their bites to be noticeable will have no serious medical consequences.

Medically significant spider venoms include various combinations and concentrations of necrotic agents, neurotoxins, and pharmacologically active compounds such as serotonin. Worldwide only two spider venoms have impact on humans—those of the widow and recluse spiders. Unlike snake and scorpion envenomation, widow and recluse species bites rarely have fatal consequences. However, isolated spider families have a lethal neurotoxic venom: the wandering spider in Brazil and the funnel web in Australia. However, due to limited contact between these spiders and humans, deaths have always been rare, and since the introduction of anti-venom in Australia, there have been no funnel web related deaths.

Since envenomation is completely voluntary, all venomous snakes are capable of biting without injecting venom into a person. Snakes may deliver such a "dry bite" rather than waste their venom on a creature too large for them to eat, a behaviour called venom metering. However, the percentage of dry bites varies among species: 80 percent of bites inflicted by sea snakes, which are normally timid, do not result in envenomation, whereas only 25 percent of pit viper bites are dry. Furthermore, some snake genera, such as rattlesnakes, significantly increase the amount of venom injected in defensive bites compared to predatory strikes.

Some dry bites may also be the result of imprecise timing on the snake's part, as venom may be prematurely released before the fangs have penetrated the person. Even without venom, some snakes, particularly large constrictors such as those belonging to the Boidae and Pythonidae families, can deliver damaging bites; large specimens often cause severe lacerations, or the snake itself pulls away, causing the flesh to be torn by the needle-sharp recurved teeth embedded in the person. While not as life-threatening as a bite from a venomous species, the bite can be at least temporarily debilitating and could lead to dangerous infections if improperly dealt with.

While most snakes must open their mouths before biting, African and Middle Eastern snakes belonging to the family Atractaspididae are able to fold their fangs to the side of their head without opening their mouth and jab a person.

In the developing world most snakebites occur in those who work outside such as farmers, hunters, and fishermen. They often happen when a person steps on the snake or approaches it too closely. In the United States and Europe snakebites most commonly occur in those who keep them as pets.

The type of snake that most often delivers serious bites depends on the region of the world. In Africa it is mambas, Egyptian cobras, puff adders, and carpet vipers. In the Middle East it is carpet vipers and elapids. In Central and South America it is snakes of the "Bothrops" and "Crotalus" types, the latter including rattlesnakes. In North America, rattlesnakes are the primary concern, and up to 95% of all snakebite-related deaths in the United States are attributed to the western and eastern diamondback rattlesnakes. In South Asia it was previously believed that Indian cobras, common kraits, Russell's viper and carpet vipers were the most dangerous; other snakes, however, may also cause significant problems in this area of the world.

Bites from "Latrodectus" occur usually because of accidental contact with the spiders. The species are not aggressive to humans naturally, but may bite when trapped. As such, bite incidents may be described as accidents. Reports of epidemics were associated with agricultural areas in Europe in the last two centuries. However the European spider is associated with fields and humans come in contact only during harvest. For example, in the 1950s researchers believed that three bites happened each year and with an epidemic up to 180 each year.

Conversely, redback and North American black widows live in proximity with people and several thousand black widow bites are reported to Poison Control in the United States each year. About 800 are reported by medical personnel. Amongst those 800 bites only a dozen had major complications and none were fatal.

In Perth, Australia, for example there were 156 bites in children from redback spiders over 20 years. Twice as many boys were bitten as girls, mostly toddlers. A third of the children developed latrodectism and there were no deaths.

Bed bug bites are caused by bed bugs primarily of two species "Cimex lectularius" (the common bed bug) and "Cimex hemipterus". Infestation is rarely due to a lack of hygiene. These insects feed exclusively on blood and may survive a year without eating. They are attracted by body warmth and carbon dioxide. Transfer to new places is usually in the personal effects of the human they feed upon.

Dwellings can become infested with bed bugs in a variety of ways, such as:

- Bugs and eggs inadvertently brought in from other infested dwellings on a visiting person's clothing or luggage;

- Infested items (such as furniture especially beds or couches, clothing, or backpacks) brought in a home or business;

- Nearby dwellings or infested items, if easy routes are available for travel, e.g. through ducts or false ceilings;

- Wild animals (such as bats or birds) that may also harbour bed bugs or related species such as the bat bug;

- People visiting an infested area (e.g. dwelling, means of transport, entertainment venue, or lodging) and carrying the bugs to another area on their clothing, luggage, or bodies. Bedbugs are increasingly found in air travel.

- Though bed bugs will feed on pets, they do not live or travel on the skin of their hosts, and pets are not believed a factor in their spread.

Cat bites can often be prevented by:

- instructing children not to tease cats or other pets.

- being cautious with unfamiliar cats.

- approaching cats with care, even if they appear to be friendly.

- avoiding rough play with cats and kittens.

Rough play causes is perceived as aggressive. This will lead to the cat being defensive when approached by people. Preventing cat bites includes not provoking the cat.

Over 400,000 cat bites are reported each year in the US, though the actual number of bites is much higher since many such bites are under-reported. 40 million households in the United States have domestic cats. Data on the number of people bitten or scratched by cats is limited because most of these incidents are not reported; however, 20%-80% of cat bites and scratches become infected. Cat-scratch disease or cat-scratch fever, an infection that causes fever and swollen lymph nodes, can develop from cat scratches even if they only break the surface of the skin. Based on reports of people treated for cat bites at hospitals, women are most likely to be victims of cat bites and scratches. Because of their smaller build, children are more likely to be bitten on their head, neck and face. Adults are more likely to bitten on the hands and arms. Those who are immunocompromised are more susceptible to infection from a cat bite.

Many species of arthropods (insects, arachnids and others) regularly or occasionally bite or sting human beings. Insect saliva contains anticoagulants and enzymes that cause local irritation and allergic reactions. Insect venoms can be delivered by their stingers, which often are modified ovipositors, or by their mouthparts. Insect, spider and scorpion venom can cause serious injury or death. Dipterans account for the majority of insect bites, while hymenopterans account for the majority of stings. Among arachnids spider bites are the most common. Arthropods bite or sting humans for a number of reasons including feeding or defense. Arthropods are major vectors of human disease, with the pathogens typically transmitted by bites.

A number of other symptoms may occur from either the bite of the bed bugs or from their exposure. Anaphylaxis from the injection of serum and other nonspecific proteins has been rarely documented. Due to each bite taking a tiny amount of blood, chronic or severe infestation may lead to anemia. Bacterial skin infection may occur due to skin break down from scratching.

Systemic poisoning may occur if the bites are numerous. Exposure to bed bugs may trigger an asthma attack via the effects of airborne allergens although evidence of this association is limited. There is no evidence that bed bugs transmit infectious diseases even though they appear physically capable of carrying pathogens and this possibility has been investigated. The bite itself may be painful thus resulting in poor sleep and worse work performance.

Similar to humans, pets can also be bitten by bed bugs. The signs left by the bites are the same as in case of people and cause identical symptoms (skin irritation, scratching etc).

An escharotic is a substance that causes tissue to die and slough off. Examples include acids, alkalis, carbon dioxide, metallic salts and sanguinarine, as well as certain medicines like imiquimod. Escharotics known as black salves, containing ingredients such as zinc chloride and sanguinarine containing bloodroot extracts, were traditionally used in herbal medicine as topical treatments for localised skin cancers, but often cause scarring and can potentially cause serious injury and disfigurement. Consequently, escharotic salves are very strictly regulated in most western countries and while some prescription medicines are available with this effect, unauthorized sales are illegal. Some prosecutions have been pursued over unlicensed sales of escharotic products such as Cansema.

Loxoscelism () is a condition occasionally produced by the bite of the recluse spiders (genus "Loxosceles"). The area becomes dusky and a deep open sore forms as the skin around the bite dies (necrosis). It is the only proven type of necrotic arachnidism in humans. While there is no known therapy effective for loxoscelism, there has been research on antibiotics, surgical timing, hyperbaric oxygen, potential antivenoms and vaccines. Because of the number of diseases that may mimic loxoscelism, it is frequently misdiagnosed by physicians.

Loxoscelism was first described in the United States in 1879 in Tennessee. Although there are up to 13 different "Loxosceles" species in North America (11 native and two nonnative), "Loxosceles reclusa" is the species most often involved in serious envenomation. "Loxosceles reclusa" has a limited habitat that includes the Southeast United States. In South America, "L. laeta", "L. intermedia" (found in Brazil and Argentina), and "L. gaucho" (Brazil) are the three species most often reported to cause necrotic bites.

Anti-venoms are commercially prepared antibodies to toxins in animal bites. They are specific for each bite. There are several anti-venoms commercially available in Brazil, which have been shown to be effective in controlling the spread of necrosis in rabbits. When administered immediately, they can almost entirely neutralize any ill effects. If too much time is allowed to pass, the treatment becomes ineffective. Most victims do not seek medical attention within the first twelve hours of being bitten, and these anti-venoms are largely ineffective after this point. Because of this, anti-venoms are not being developed more widely. They have, however, been proven to be very effective if administered in a timely manner and could be utilized in Brazil as a legitimate technique.

The majority of individuals who receive a sting from an insect experience local reactions. It is estimated that 5-10% of individuals will experience a generalized systemic reaction that can involve symptoms ranging from hives to wheezing and even anaphylaxis. In the United States approximately 40 people die each year from anaphylaxis due to stinging insect allergy. Potentially life-threatening reactions occur in 3% of adults and 0.4–0.8% of children.

The histomorphologic appearance of insect bites is usually characterized by a wedge-shaped superficial dermal perivascular infiltrate consisting of abundant lymphocytes and scattered eosinophils. This appearance is non-specific, i.e. it may be seen in a number of conditions including:

- Drug reactions,

- Urticarial reactions,

- Prevesicular early stage of bullous pemphigoid, and

- HIV related dermatoses.

Feeding bites have characteristic patterns and symptoms, a function of the feeding habits of the offending pest and the chemistry of its saliva.

An eschar (; Greek: "eschara") is a slough or piece of dead tissue that is cast off from the surface of the skin, particularly after a burn injury, but also seen in gangrene, ulcer, fungal infections, necrotizing spider bite wounds, spotted fevers and exposure to cutaneous anthrax. The term "eschar" is not interchangeable with "scab". An eschar contains necrotic tissue, whereas a scab is composed of dried blood and exudate.

Black eschars are most commonly attributed to anthrax, which may be contracted through herd animal exposure, but can also be obtained from "Pasteurella multocida" exposure in cats and rabbits. A newly identified human rickettsial infection, "R. parkeri" rickettsiosis, can be differentiated from Rocky Mountain spotted fever by the presence of an eschar at the site of inoculation.

Eschar is sometimes called a "black wound" because the wound is covered with thick, dry, black necrotic tissue.

Eschar may be allowed to slough off naturally, or it may require surgical removal (debridement) to prevent infection, especially in immunocompromised patients (e.g. if a skin graft is to be conducted).

If eschar is on a limb, it is important to assess peripheral pulses of the affected limb to make sure blood and lymphatic circulation is not compromised. If circulation is compromised, an escharotomy, or surgical incision through the eschar, may be indicated.

Insect sting allergy is the term commonly given to the allergic response of an animal in response to the bite or sting of an insect. Typically, insects which generate allergic responses are either stinging insects (wasps, bees, hornets and ants) or biting insects (mosquitoes, ticks). Stinging insects inject venom into their victims, whilst biting insects normally introduce anti-coagulants into their victims.

The great majority of insect allergic animals just have a simple allergic response – a reaction local to the sting site which appears as just a swelling arising from the release of histamine and other chemicals from the body tissues near to the sting site. The swelling, if allergic, can be helped by the provision of an anti-histamine ointment as well as an ice pack. This is the typical response for all biting insects and many people have this common reaction.

Mosquito allergy may result in a collection of symptoms called skeeter syndrome that occur after a bite. This syndrome may be mistaken for an infection such as cellulitis.

In anaphylactic patients the response is more aggressive leading to a systemic reaction where the response progresses from the sting site around the whole body. This is potentially something very serious and can lead to anaphylaxis, which is potentially life-threatening.

Chiggers are commonly found on the tip of blades of grasses to catch a host, so keeping grass short, and removing brush and wood debris where potential mite hosts may live, can limit their impact on an area. Sunlight that penetrates the grass will make the lawn drier and make it less favorable for chigger survival.

Chiggers seem to affect warm covered areas of the body more than drier areas. Thus, the bites are often clustered behind the knees, or beneath tight undergarments such as socks, underwear, or brassieres. Areas higher in the body (chest, back, waist-band, and under-arms) are affected more easily in small children than in adults, since children are shorter and are more likely than adults to come in contact with low-lying vegetation and dry grass where chiggers thrive. An exceptional case has been described in the eye, producing conjunctivitis.

Application of repellent to the shoes, lower trousers and skin is also useful. Because they are found in grass, staying on trails, roads, or paths can prevent contact. Dusting sulfur is used commercially for mite control and can be used to control chiggers in yards. The dusting of shoes, socks and trouser legs with sulfur can be highly effective in repelling chiggers.

Another good strategy is to recognize the chigger habitat to avoid exposure in the first place. Chiggers in North America thrive late in summer, in dry tall grasses and other thick, unshaded vegetation. Insect repellents containing one of the following active ingredients are recommended: DEET, catnip oil extract (nepetalactone), citronella oil or eucalyptus oil extract. However, in 1993 issue a study reported on tests of two commercial repellents: DEET and citrus oil: "All chiggers exposed on the filter papers treated with DEET died and did not move off the treated papers. None of the chiggers that were placed on papers treated with citrus oil were killed." It was concluded that DEET was more effective than citrus oil.

Chiggers can also be treated using common household vinegar (5% acetic acid).

Immediate treatment consists of rinsing the bite site in cold water. If not too painful, ice the bite site. This constricts the blood vessels so the venom does not spread. Also recommended is papain, an enzyme that breaks down protein. Papain can be found in meat tenderizer and papaya. This deactivates the majority of the centipede venom's proteins. Depending on the type of centipede and level of envenomation, this treatment may not degrade the entire venom dose and residual pain will remain.

Individuals who are bitten by centipedes are sometimes given a urine test to check for muscle tissue breakdown and/or an EKG to check for heart and vascular problems.

Reassurance and pain relief is often given in the form of painkillers, such as non-steroidal anti-inflammatory medications, antihistamines and anti-anxiety medications. In a severe case the affected limb can be elevated and administered diuretic medications.

Wound care principles and sometimes antibiotics are used to keep the wound itself from becoming infected or necrotic.

In Barbados, a folk remedy involves applying a freshly cut onion to the site of the injury "bite" for 10 minutes. Repeat until relief is obtained.

Trombiculosis, trombiculiasis, or trombiculidiasis is a rash caused by trombiculid mites which is often referred to as a chigger bite.

A centipede bite is an injury resulting from the action of a centipede's forcipules, pincer-like appendages that pierce the skin and inject venom into the wound. Such a wound is not technically a bite, as the forcipules are 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 large paired forcipules of the centipede.

The centipede's venom causes pain and swelling in the area of the bite, and may cause other reactions throughout the body. The majority of bites are not life-threatening to humans and present the greatest risk to children and those who develop allergic reactions.

While obviously preventable by staying away from rodents, otherwise hands and face should be washed after contact and any scratches both cleaned and antiseptics applied. The effect of chemoprophylaxis following rodent bites or scratches on the disease is unknown. No vaccines are available for these diseases.

Improved conditions to minimize rodent contact with humans are the best preventive measures. Animal handlers, laboratory workers, and sanitation and sewer workers must take special precautions against exposure. Wild rodents, dead or alive, should not be touched and pets must not be allowed to ingest rodents.

Those living in the inner cities where overcrowding and poor sanitation cause rodent problems are at risk from the disease. Half of all cases reported are children under 12 living in these conditions.

When proper treatment is provided for patients with rat-bite fever, the prognosis is positive. Without treatment, the infection usually resolves on its own, although it may take up to a year to do so. A particular strain of rat-bite fever in the United States can progress and cause serious complications that can be potentially fatal. Before antibiotics were used, many cases resulted in death. If left untreated, streptobacillary rat-bite fever can result in infection in the lining of the heart, covering over the spinal cord and brain, or in the lungs. Any tissue or organ throughout the body may develop an abscess.