White-tail spiders: identification, bites, and the myth that won't die

No Australian spider carries a scarier reputation on thinner evidence than the white-tail. Ask around and you'll hear it causes flesh-eating ulcers — a claim that has been directly studied and doesn't hold up. Here's what a white-tail actually looks like, what its bite really does, and why you keep finding them in the bathroom in summer.

What a white-tail spider looks like

White-tails (mainly Lampona cylindrata and Lampona murina) are slender, cigar-shaped spiders, dark grey to charcoal, with the giveaway feature right at the end: a distinct white or cream spot on the tip of the abdomen. Legs are dark and slightly banded. They don't build a web to live in — you'll see them walking, usually on walls or floors at night.

Male vs female

Females are the larger sex — body up to about 18mm, with a legspan around 40mm — and slightly bulkier through the abdomen. Males run smaller (body to roughly 12mm), with a slimmer profile and proportionally longer legs. Both sexes carry the white tail-spot, so identification doesn't depend on telling them apart — but the big one that startled you on the bathroom wall was probably a female.

Why they're in your house

White-tails are hunters of other spiders — black house spiders are a favourite prey. That's the key to understanding them: they come inside because your house has other spiders to eat, and they wander at night hunting rather than sitting in a web. Activity peaks in the warmer months, and they have an unfortunate habit of sheltering in fabric during the day — clothes left on the floor, towels, bedding, shoes. Most bites happen exactly that way: the spider is trapped against skin by fabric, not attacking.

The bite: facts vs the myth

The claim that white-tail bites cause necrotic, flesh-eating ulcers became Australian folklore in the 1980s. It has since been properly tested: a study of 130 verified white-tail bites — where the spider was caught and identified — found not a single case of necrosis. The typical real bite causes local pain, a red mark, and sometimes itchiness for a few days: unpleasant, comparable to a bee sting, and not medically dangerous. Reported "spider bite ulcers" investigated by doctors routinely turn out to be infections or other conditions with no spider involved at all. In short: treat the white-tail with respect, but the horror stories aren't supported by the evidence.

First aid for a bite

• Wash the site with soap and water, apply a cold pack for the pain
• Don't apply pressure bandages — that's for funnel-web bites, not these
• Keep an eye on it: see a doctor if pain worsens, the site looks infected, or symptoms persist beyond a few days
• If you can safely catch or photograph the spider, do — identification helps any medical assessment. Better Health Channel's bites and stings guidance covers first aid in detail

Keeping them out

Because white-tails follow their prey, the lasting fix is controlling the spiders they hunt. Clear webbing spiders from windows, eaves and subfloors (see our black house spider guide — their favourite meal), seal gaps under doors and around windows, and shake out clothes and towels that have been on the floor in summer. A professional spider treatment that knocks down the webbing spider population removes the food supply, and the white-tails move on — that's the approach we take across Melbourne homes and suburbs.

Frequently asked questions

Are white-tail spiders dangerous?

Not in the way folklore says. Verified bites cause local pain, redness and sometimes itchiness — a study of 130 confirmed bites found no cases of the flesh-eating necrosis the species is blamed for. Painful, yes; dangerous to a healthy adult, no.

Can a white-tail spider kill you?

No. There are no confirmed deaths from white-tail spider bites, and verified bites don't cause systemic poisoning. The medically serious Australian spiders are funnel-webs and, to a lesser extent, redbacks — both covered by antivenoms.

What do white-tail spiders look like?

Slender, cigar-shaped, dark grey to charcoal, 12–18mm body, with a distinct white spot on the tip of the abdomen — that spot is the giveaway. They wander rather than sitting in webs, usually seen on walls at night.

Why do I keep finding white-tails in my house?

They hunt other spiders, especially black house spiders — so a house with webbing spiders around windows and eaves is a stocked pantry. Control the prey spiders and white-tails stop visiting.

Where do white-tails hide during the day?

In fabric and tight dark spots: clothes on the floor, towels, bedding, shoes, and behind furniture. That's why most bites happen when someone puts on clothing or rolls onto one — shake fabric out in summer.

A1 Pest & Weed Control handles this for homes and businesses across Melbourne — licensed technicians, guaranteed results, and fast response: 0411 859 516 or get a free quote.