If you find a spider indoors, use a spider identifier before deciding whether to spray, remove it or call a pest professional. A sound identification is an assessment based on several clues—such as body shape, markings, web and location—not a certainty based on colour or one photograph. In New Zealand, don’t handle an unfamiliar spider, especially if you suspect it could be a katipō. Photograph it from a safe distance, record where you found it and seek local advice if the identification remains uncertain. The steps below help you judge what you’re seeing and choose a proportionate response.
A spider identifier can help narrow down what you’ve found, but the result depends on the quality of the evidence. A clear image of the body and legs, plus information about the web and where the spider was seen, is more useful than a close-up of one coloured marking. Even then, an exact species identification may not be possible from a photograph.
Identification has several levels. First, establish whether the animal is a true spider or another arachnid. Then consider its broader type and, only if the available features support it, a likely species. A harvestman, for example, is an arachnid but not a true spider; its body appears to have one main section, while a spider has two main body sections joined by a narrower connection. Poor lighting, a missing leg or a blurred image can make such differences hard to see.
Age and condition matter, too. Young spiders may not have the adult appearance shown in a reference image, and colours can look different under indoor lighting. Identification tools may also return a plausible-looking match for a species that is not the best local fit. Treat an app result as a lead to check, not proof.
Use this process to gather useful evidence without getting close enough to touch the spider.
When sharing an image for identification, include the location and a short description of where the spider was found. Avoid sending only a heavily cropped or edited picture: it may remove the details needed to assess the match. If the spider has disappeared, don’t search by hand through a dark corner or stored items to find it again.
A spider identifier works best when each observation is treated as one piece of evidence. The table below shows what common clues can contribute and where their limits lie.
| Clue | What to record | What it may help show | What it cannot prove |
|---|---|---|---|
| Body shape | Overall proportions and whether the two main body sections are visible | Whether the animal may be a true spider or another arachnid | The exact species, especially in a poor image |
| Markings and colour | Patterns on the body, noting the light and image quality | A possible match when combined with other features | That a spider is a particular species or dangerous |
| Size | Approximate body length and leg span separately | A comparison with reference images | Identity on its own; individuals can differ in size and age |
| Web | Shape, location and whether the spider was present | Clues about the spider’s habits or broad group | Which spider made it; webs may be abandoned or obscured |
| Location | Room, outdoor setting and nearby shelter or vegetation | Context that may make some local possibilities more likely | A confirmed identification based on habitat alone |
| Behaviour | Whether it was stationary, web-dwelling or moving across a surface | Context for understanding the sighting | A reliable test of whether it is harmful |
For New Zealand homeowners, a suspected katipō deserves particular caution: don’t try to confirm the identification by handling it. Colour or a single photograph is not enough to settle an uncertain match. Keep your distance and seek local expert advice if you think one may be present.
If you have no reason to suspect a species of concern and the spider is not creating a practical problem, a chemical treatment may not be necessary. Many spiders feed on other small invertebrates. You can leave it undisturbed or arrange removal if you prefer, provided you can do so without handling it or putting yourself at risk.
If you are unsure whether it is safe to move, don’t improvise with bare hands or a jar held close to it. Keep the area clear and ask someone with appropriate experience to advise you.
Keep people and pets away from the immediate area, take photographs from a distance if possible, and contact a local pest professional or another suitable identification service. Share the location and any web or habitat details, not just the spider’s colour. If the spider is in a place where it cannot be left safely, explain that when asking for assistance.
New Zealand has its own spider species and regional variation, so an overseas guide or app match may be misleading. If a possible katipō is involved, avoid contact and seek local advice rather than attempting to capture it for a clearer picture.
Repeated sightings are a reason to inspect likely entry points and sheltered areas, but they do not by themselves prove a serious infestation or mean that the whole home needs spraying. Record where and how often spiders appear, and look for patterns such as gaps around doors or windows, damaged screens, cluttered storage areas or a steady supply of other insects.
If sightings continue across several rooms, or you find numerous webs or egg sacs, a pest professional can assess the conditions and recommend a response. Ask whether the proposed treatment addresses the source of the problem and what preparation, follow-up or precautions are required. The answer should be based on what is actually present, not simply on the word “spider.”
Wash the area gently with soap and water, and use a cold pack wrapped in cloth if that helps with discomfort. Don’t cut or suck the wound, or apply a tight band. Seek medical advice if symptoms are concerning, worsening or unusual; severe symptoms such as difficulty breathing require emergency help. Don’t try to catch the spider after a bite. A photograph taken safely may help, but the person’s health comes first.
Prevention is often more useful than treating every individual spider. Start with low-risk measures that reduce access to indoor spaces and make sheltered areas easier to inspect:
Use pesticide only when there is a clear reason to do so, and follow the product label exactly. Don’t spray an unidentified spider at close range or apply chemicals in areas where children or pets may contact them. If you hire a pest-control company, ask what evidence supports treatment, which areas will be treated, what the work includes, and what safety or re-entry instructions apply. Request the proposed scope and cost in writing so you can compare like with like.
A professional assessment makes sense when the spider may be a species of concern, sightings are frequent, or you cannot safely manage the situation yourself. The value of the visit is not just removal: the provider should explain what was identified, what remains uncertain and why the recommended response is appropriate.
An app can suggest possibilities from a photograph, but its result is not a confirmed identification. Image quality, the spider’s age and whether the app’s reference set suits New Zealand can all affect the match. Use it as a starting point and compare several features.
If it is safe, take clear images from more than one angle and include the whole spider, its markings and the web or nearby setting. Add an approximate size and where it was found. Don’t move closer, handle it or place an object beside it just to improve the photograph.
No. A single sighting does not establish that spiders are breeding throughout the home or that treatment is needed. Repeated sightings, multiple webs or other signs are reasons to inspect the area and consider professional advice.
Not necessarily. If the spider is not creating a problem and you can leave it undisturbed, pesticide may be unnecessary. If you don’t know what it is or don’t feel safe removing it, keep your distance and ask for help instead of handling it.
Don’t judge by size or colour alone, and don’t handle a spider to check its markings. If you suspect a species of concern or cannot identify it confidently, photograph it from a safe distance and seek local advice. Treat a bite according to the person’s symptoms, not an uncertain visual guess.
Contact one if sightings are persistent, the spider may be a species of concern, or the situation is difficult to manage safely. Ask how the provider will identify the problem, what treatment is proposed and what precautions or follow-up are included.
A spider identifier is most useful when it supports a measured decision, not when it encourages a quick guess. Gather several clues from a safe distance, account for New Zealand’s local species and keep your response proportionate. If identity or risk remains uncertain, avoid handling the spider and seek suitable professional advice before choosing a treatment.
