How dangerous is the false widow spider?

The false widow spider is not aggressive and will usually only bite a person when it feels threatened.

Its preferred option is to flee to safety. Their venom is a precious resource that takes time to generate and so they will use it very sparingly.

"The tiniest amounts of venom – about 1,000th of a raindrop – can cause medically significant symptoms in humans that are about 250,000 times larger than them."

Dr John Dunbar
Venom Systems Laboratories, NUI Galway


As venomous as the true black widow spider

False widow spider illustrated graphic

Times more venomous than our native spiders

False widow spider bite symptoms

A bite from a false widow is not fatal and the majority of bites are mostly mild.

Common Symptoms

  • Mild Pain
  • Redness
  • Swelling
Uncommon Symptoms

  • Tremors
  • Nausea
  • Vomiting
  • Dizziness
  • Debilitating pain
  • Impaired mobility

Rare Symptoms

  • Blistering
  • Allergic reaction
  • Tissue necrosis
  • Severe bacterial infection

The majority of false widow spider bites in Ireland and the UK occur inside the home when the spider has been accidentally trapped in clothing or bedsheets.

"Dry biting" is when the spider bites without releasing any venom.
This appears to be its preferred mode of defence. For this reason, false widow bites are usually only as painful as a bee or a wasp sting.

How to treat a false widow spider bite

A bite from a false widow is not fatal and the majority of bites are mostly mild.


False widow bite treatment clean the wound

Clean the wound by washing the area with soap and water

False widow bite treatment cool the wound

Apply a cloth cooled with water or an ice pack for 10 minutes

False widow bite treatment cover the wound

Avoid infection by covering and not scratching the wound 

False Widow spider bite help
Seek urgent medical advice if vomiting, radiating pain and/or hot/cold flushes develop and for bites on or around the eye.
False widow venomous spider

The National Poisons Information Centre (NPIC)

Contact the NPIC, a GP or pharmacist if pain persists or swelling develops.

How to avoid a false widow bite

Close windows at night

Close Windows

Close windows in the evening when the spiders become more active and may enter your home for warmth.

Clean and dust frequently

Clean and Dust

Removing webs and cleaning regularly will discourage the spiders from staying in your home.

Shake out clothing

Check Clothing

Shake out clothing before contact, the spiders often get trapped there and may bite in defence.

Vacum carpets regularly

Vacuum Floors

Keeping carpets clean and free of debris will discourage spiders and their prey from settling in.

Wear gloves when working outside

Wear Gloves

Wear gloves when working outside or in sheds. Store gloves where the spiders can not enter them.

Clean webs from wheelie bins

Check Wheelie Bins

Keep the bin lid and handles free of spider webs. Wear protective gloves when handling the bin.

False widow spider species in Ireland

The three most common false widow spiders in Ireland and Britain are Steatoda nobilis, Steatoda grossa, and Steatoda bipunctata.

Noble false widow spider

Steatoda nobilis

Cupboard spider

Steatoda grossa

Rabbit hutch spider

Steatoda bipunctata

False widow spider in Ireland stories

Met my first false widow today!

Met my first false widow today!

This morning, a fresh sunny day in April in coastal Galway, just as we were getting the kids ready to leave for school, a false widow spider started making it's way from the front door across our hallway. It wasn't moving too quickly so I was able to get an envelope to put under it and then take it outside. Once outside, I immediately noticed it shot...

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False widow spider in my pajamas!

False widow spider in my pajamas!

A Close Encounter in Cork Hey there! Hope you're keeping well, I actually stumbled across my first false widow spider earlier today and identified it with the help of the internet. I have nothing but good things to say about it honestly! I typically tend to keep my pajamas on if I know I'm not going out for the day, so I had them on for quite a while. I...

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False widow spider in my house

False widow spider in my house

Lots of false widow spider webs Over the past year I have noticed a lot of false widow spider webs in my back garden around my shed. I recognised them due to their messy box/sail like shape - as opposed to the traditional neat patterned web of a typical garden spider. The spiders are only active at night so I wasn't too concerned. But I was very...

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Baby false widow spider bite?

Baby false widow spider bite?

Was it a baby false widow spider bite? I'm pretty sure I sustained a baby false widow spider bite this summer but I'm not 100% sure. I have seen loads of the adults recently, really for the first time too. A neighbour told me last year that they had a lot of false widow spiders in their back garden. That year I started to notice a few around the outside...

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