Short answer: No. Spitting spiders (family Scytodidae) are not considered dangerous to people. They are small, slow-moving and shy, and bites on humans are rarely reported. Their famous sticky spray is a hunting tool used on insects and other small animals from about a centimetre away.
The main reason people worry about them is that they are sometimes mistaken for the brown recluse. The two can be told apart with a few simple clues, covered below.
What is a spitting spider?
“Spitting spider” is the common name for spiders in the family Scytodidae. According to the World Spider Catalog, the family currently contains around 260 accepted species in four genera. Most of them belong to the genus Scytodes.
The species people meet most often is Scytodes thoracica. Its native range covers Europe, North Africa and a broad band of temperate Asia, and it has been introduced to North America, Argentina, South Africa, India, Australia and New Zealand. In cooler climates it tends to live inside heated buildings, which is why many people first notice one on a wall or ceiling at night.
Other Scytodes species live in warmer regions and can look quite different, so the details on this page focus on S. thoracica unless stated otherwise.
How to recognize one
No single feature, and certainly not colour alone, is enough to identify a spider. Spitting spiders are easier than most to recognize, though, because several unusual traits tend to appear together.
| Clue | What to look for (Scytodes thoracica) |
|---|---|
| Body shape | A high, domed carapace that rises toward the back, roughly as large as the abdomen |
| Size | Body length about 3.5–6 mm; females are larger than males (leg span is wider) |
| Colour and markings | Pale yellow to light brown, covered in black spots and stripes on both the carapace and the abdomen |
| Legs | Long and thin, often with dark bands |
| Eyes | Six eyes arranged in three pairs, rather than the more common eight |
| Web | No catching web; it hunts by wandering |
| Behaviour | Mostly active at night and walks slowly, though it can make short, sudden dashes |
| Where it is found | Indoors in many regions, in quiet corners, cupboards, cellars and wall–ceiling angles |
If the spider you found is small and brownish but does not match these clues, our small brown spider identification guide and the page on brown spiders with long legs in the house cover other common candidates.
How the “spitting” works
A spitting spider creeps slowly toward its prey, feeling ahead with its long front legs, and stops roughly a centimetre away. It then ejects a sticky mixture from its fangs that lands across the prey in a zigzag pattern and glues it to the surface. Once the prey is held down, the spider moves in and bites.
The spray comes from the venom glands, which in this family are greatly enlarged and fill much of the domed carapace. That is the reason for the spider’s unusual shape.
A high-speed video study of Scytodes thoracica by Suter and Stratton (2009) measured just how fast this happens:
- the material left the fangs at speeds of up to about 28 metres per second;
- a full spit was usually over in less than 30 milliseconds;
- the fangs swung from side to side hundreds of times per second, up to roughly 1,700 times, which produces the zigzag pattern.
Is there venom in the spit?
The spray is often described as a mix of silk-like threads, glue and venom, because it comes out through the venom duct. How much the venom actually contributes is less clear. Suter and Stratton point to earlier work that found the spit had no toxic effect when applied to the outside of prey, and suggest that the shrinking threads and glue do most of the work of holding prey still. In other words, the spray restrains prey; the bite that follows is what subdues it.
Spitting spiders also use the spray in defence, for example against other spiders that threaten them.
Can a spitting spider hurt you?
Spitting spiders do have venom, as nearly all spiders do. Having venom is not the same as being dangerous to people, though, and nothing suggests these spiders pose a medical risk.
- Bites are uncommon. They are small, mostly nocturnal spiders that avoid contact with people, and their fangs are tiny.
- Specialists consider them harmless. Arachnologist Rick Vetter of the University of California, Riverside, lists spitting spiders among the harmless spiders that are often mistaken for recluses.
- The spray is built for small prey. It works at very short range on insects and other small animals.
As with any spider, a bite could cause brief local pain, redness or itching, and a person with a history of serious allergic reactions should be more cautious with any bite or sting.
Spitting spider or brown recluse?
This is the comparison that matters most for safety. The two groups share the same six-eye arrangement, so eyes alone will not separate them. Body markings will, quite quickly.
| Feature | Spitting spider (Scytodes) | Brown recluse (Loxosceles reclusa) |
|---|---|---|
| Eyes | Six, in three pairs | Six, in three pairs |
| Carapace shape | Strongly domed, humped in side view | Relatively flat |
| Carapace markings | Black spots and/or stripes | A dark violin-shaped mark, not reliable on its own |
| Abdomen | Spotted or striped | Plain, with no pattern |
| Range | Varies by species; S. thoracica is widespread through human movement | Limited to parts of the central and southern United States |
A patterned abdomen is the clearest single sign: Vetter notes that recluse abdomens have no colour pattern at all, so spots or stripes there should rule out a recluse. Location also matters. A spider found well outside the brown recluse’s range is very unlikely to be one, whatever it looks like.
What scientists have learned about their venom
Spider venoms are studied as possible sources of new drugs and insecticides, and spitting spiders have been part of that work. In 2016, a team including researchers from the University of Queensland and Lewis & Clark College described three venom peptides from Scytodes thoracica. The peptides showed no significant activity against the human ion channels and nervous-system targets they were tested on, and injecting them into crickets and blowflies did not paralyse or kill the insects. Their natural role is still unknown, and many other peptides from this spider have not yet been tested.
So far, this research says more about how little we know about these venoms than about any risk to people.
Found one at home? What to do
A spitting spider indoors is not a sign of a problem, and there is no need to treat it as one. These spiders feed on insects and other small spiders, so they do a modest amount of pest control. If you would rather not share the room:
- gently cover it with a glass or jar, slide a piece of card underneath, and move it outdoors or to a garage or shed;
- reduce clutter in cupboards and corners where they shelter during the day;
- seal obvious gaps around doors and windows to cut down on the insects they hunt.
For more on why spiders turn up indoors and what they eat there, see what house spiders eat.
If you think you have been bitten
Many skin problems blamed on spiders turn out to have other causes, including insect bites and bacterial infections. Dermatologists and arachnologists warn that a red, raised or slow-healing sore should not be assumed to be a spider bite. If you did not see a spider bite you, treat the problem as an unexplained skin issue and get it checked if it does not settle.
For a minor bite, general first-aid advice from poison-control services is to:
- wash the area with soap and water;
- apply a cool, damp cloth or a wrapped cold pack for 10–20 minutes;
- use an over-the-counter antihistamine or hydrocortisone cream for itching if needed.
Get medical advice if symptoms get noticeably worse, spread beyond the bite area, show signs of infection (pus, increasing redness, swelling or pain), or if you have a history of serious allergic reactions. Call emergency services straight away for swelling of the face, lips or throat, or difficulty breathing.
Where to get help: In the United States, Poison Control is available on 1-800-222-1222. In the UK, use NHS 111 for advice or 999 in an emergency. In Australia, the Poisons Information Centre is on 13 11 26. Elsewhere, contact your local poison centre or emergency number. This page is general information, not medical advice.
Frequently asked questions
Do spitting spiders spit at people?
Their spray is a prey-capture and defence tool that works at a range of about a centimetre, aimed at insects and other small animals. Spitting spiders tend to avoid people rather than confront them.
Do spitting spiders build webs?
Not to catch prey. They wander and hunt, mainly at night. Females carry their egg sac in their jaws or beneath their body until the young hatch.
Are spitting spiders poisonous?
“Poisonous” describes something harmful to eat or touch. Spiders are venomous instead, meaning they inject venom with a bite. Spitting spiders have venom, but they are not considered a medical threat to people.
Do spitting spiders live in the UK, US or Australia?
Yes. Scytodes thoracica is native to Europe, including Britain, where it is recorded mostly in southern counties. The World Spider Catalog lists it as introduced to North America and Australia, among other regions.
For other spiders that people commonly ask about, browse the Spider Bite & Danger section or the Spider Types hub. If you are still unsure what you found, the spider identification guide walks through the clues step by step.
References
- World Spider Catalog (2026). Family Scytodidae, genus list; and Scytodes thoracica (Latreille, 1802). Natural History Museum Bern. wsc.nmbe.ch
- Suter, R. B. & Stratton, G. E. (2009). Spitting performance parameters and their biomechanical implications in the spitting spider, Scytodes thoracica. Journal of Insect Science 9: 62. PMC3011943
- Vetter, R. S. (1999). Identifying and misidentifying the brown recluse spider. Dermatology Online Journal 5(2): 7. escholarship.org
- Ariki, N. K. et al. (2016). Characterization of three venom peptides from the spitting spider Scytodes thoracica. PLoS ONE 11(5): e0156291. PMC4881942
- British Arachnological Society. Scytodes thoracica species page. britishspiders.org.uk
- Animal Diversity Web, University of Michigan. Scytodes thoracica. animaldiversity.org
- University of California, Riverside (2017). No, that’s not a brown recluse spider bite. entomology.ucr.edu
- Poison Control (US National Capital Poison Center). Insect and spider bites: when to worry. poison.org
- NHS. Insect bites and stings. nhs.uk
- NSW Poisons Information Centre. Spiders. poisonsinfo.nsw.gov.au
