# Redback spider (Latrodectus hasselti) > A small, venomous widow spider native to Australia, notable for the female's black body with a red dorsal stripe and a medically significant bite. Source: https://insectscanner.com/species/redback-spider/ (updated 2026-10-10) ## Is it dangerous? **Venomous bite.** Bites can cause latrodectism: intense pain around the bite that can spread, sweating, muscle pain and cramping, nausea, and autonomic symptoms. Severe reactions are uncommon but possible, especially in young children, elderly or medically vulnerable people. First aid: keep the patient calm, wash the bite, and apply an ice or cold pack to relieve pain. Do not use a pressure immobilisation bandage for redback bites, as it can make the pain worse. Seek medical attention, and call emergency services for a child bitten, or for severe or spreading pain, sweating or other systemic symptoms. Doctors can provide pain relief, and antivenom may be considered for severe symptoms. **Pets:** Pets may be affected by bites; signs include pain, lethargy, vomiting, muscle tremors or paralysis. Seek veterinary care promptly if you suspect a redback bite to a pet. ## Quick facts - Scientific name: Latrodectus hasselti - Also called: Australian black widow - Order: Araneae (Spiders) - Family: Theridiidae (Comb-footed spiders) - Size: Female body length 6-10 mm, males 3-4 mm - Colours: Black, Red, Dark brown - Habitat: Sheltered, dry locations near ground level: under rocks, logs, roof eaves, sheds, garages, fence posts, and in outdoor furniture or litter; also sometimes indoors in cluttered areas. - Range: Native to mainland Australia; introduced and established in New Zealand and reported in parts of Asia and some islands via human transport. - Active: Year-round in mild climates, most active in warmer months and at night when males search for females. - Lifespan: Females typically live 1-2 years; males often die soon after mating (many do not survive to a second year). - Effect on plants: Harmless - Pest: no ## Overview The redback spider is a member of the widow spiders, best known for the distinctly marked, venomous adult female. Females build messy, tangled webs near ground level in sheltered locations and are relatively sedentary; males are much smaller and wander in search of mates. The species is native to mainland Australia and has been introduced to some nearby regions. Its bite can cause latrodectism, a painful syndrome; medical care, including pain relief and in some cases antivenom, is available when needed. ## How to identify it Adult females are compact and bulbous with a shiny black to very dark brown abdomen and a prominent red or orange dorsal stripe or hourglass marking on the upper surface of the abdomen; the underside often has a broken red-orange hourglass. Females are robust with relatively short legs. Males are much smaller, slimmer, and browner with lighter markings and lack the prominent red dorsal band. Juveniles and immature spiders are paler and may show variable markings before reaching adult coloration. - Adult females: shiny black or very dark brown, with a distinctive red or orange dorsal stripe or hourglass marking on the abdomen - Female size much larger and more rounded than males; males are smaller, slender, and brownish with lighter markings - Builds a messy, tangled web close to the ground in sheltered places; look for egg sacs and the female near the web ## Lookalikes - **Other widow spiders** (Latrodectus spp.): Other Latrodectus species (for example L. geometricus, the brown widow) differ in colour pattern and hourglass shape; redbacks have a characteristic dorsal red stripe and a broken ventral hourglass on many females. - **False black widow** (Steatoda spp.): Steatoda are generally less glossy, lack the bright red dorsal stripe, and their bites are far less medically significant. ## Life cycle - **Egg sac:** Females produce sticky, spherical egg sacs (dozens to hundreds of eggs) and guard them in the web until spiderlings emerge. - **Spiderling (juvenile):** Young spiders hatch from egg sacs and disperse from the maternal web; juveniles moult several times and gradually develop adult markings. - **Adult spider:** Adults reach sexual maturity after multiple moults; males wander to find females and mating may occur on or near the female's web. ## Diet and predators - Young eat: Small flying and crawling arthropods caught in silk webs - Adults eat: Insects and other small arthropods trapped in their sticky, tangled webs; larger prey may include bees, flies, and beetles - Predators of the young: Ants, predatory insects, other spiders and small predators - Predators of adults: Some birds, larger spiders, wasps (including spider-hunting wasps), and small mammals ## Effect on plants and gardens Redbacks do not feed on plants; they are predators of insects and other small arthropods and have little direct impact on gardens except by reducing pest insects. ## Where and when to find it Look for adult females in messy webs close to the ground in sheltered spots: under eaves, in sheds, garages, beneath outdoor furniture, under rocks and logs, and in wall cavities. Juveniles may be found on vegetation and in webs near the maternal sac. - Best time: Year-round in mild climates; most active and easier to find in warmer months and at night. - Tips: Use a long lens or a zoom rather than approaching closely. Wear gloves and avoid disturbing web retreats. Photograph the dorsal pattern from a safe distance to confirm ID. ## Fun facts - Female redbacks sometimes eat the male after mating; sexual cannibalism occurs in some cases but is not guaranteed. - Redbacks are territorial and generally remain near their webs rather than roaming. - Redback antivenom was introduced in 1956, and no deaths from redback bites have been confirmed in Australia since then. ## Frequently asked questions ### Do redback spiders bite? Yes. Female redbacks can and do bite when provoked, trapped against skin, or inadvertently handled; males seldom bite humans because they are small and not aggressive. ### Are redback spider bites dangerous? Bites can be medically significant and cause latrodectism (pain, sweating, muscle cramps). Severe outcomes are rare with prompt medical care; seek urgent medical attention for suspected bites, especially for children. ### Why is a redback in my house? They seek sheltered, dry, undisturbed locations close to food sources (insects). Indoor clutter, garages, sheds and roof spaces provide ideal retreat sites. ### How do I get rid of redback spiders? Reduce shelter and food: clear clutter, seal gaps, remove webs and egg sacs with a long-handled tool wearing gloves, and keep areas dry and well-ventilated. For heavy infestations or if you feel at risk, contact pest control. Avoid handling spiders directly. ### What should I do if bitten by a redback? Keep the person calm, wash the bite with soap and water and apply an ice or cold pack to ease pain. Do not apply a pressure bandage, and do not cut or suck the wound. Seek medical care, urgently for children or if pain is severe or spreading or other symptoms develop; doctors can give pain relief and may consider antivenom for severe symptoms. ### Where are redback spiders found? They are native across mainland Australia and have been introduced to New Zealand and some other regions through human transport; they favour human-modified habitats. --- More about this species: [iNaturalist](https://www.inaturalist.org/taxa/146765), [Wikipedia](https://en.wikipedia.org/wiki/Redback_spider). Identify insects and spiders from a photo with the Insect Scanner iPhone app: https://apps.apple.com/app/id1543946563?pt=126685406&ct=web-markdown&mt=8 Identification from photos is never certain: don't handle insects you can't identify, and get medical advice for bites, stings or allergic reactions.