You open the storeroom cupboard and find a shiny black spider in the corner, and the first question jumps up: is this the dangerous type? The reassuring truth is that most black spiders in homes are not dangerous; they hunt insects, spin webs in corners and flee when approached, biting only when pressed. But a rare type deserves caution, and telling it from others is not by color alone but by specific marks. In this guide we explain how to recognize the dangerous type, why spiders appear in your home, how to inspect and remove webs and egg sacs safely, what to do after a bite, and how to reduce their presence without random spraying.
Is a black spider dangerous?
- Most black house spiders hunt insects and spin webs in corners; the harm is slight.
- Bites are rare and usually happen when one is pressed or touched by accident.
- But a shiny black dangerous type exists, known as the black widow, which is not common.
How to recognise the dangerous type
- A shiny black body with a round swollen abdomen.
- A red or orange mark under the abdomen, often hourglass-shaped.
- An irregular sticky web near the ground in dark corners.
Do not judge by colour alone. If unsure, photograph it from a safe distance, ask a specialist, and do not touch it.
Why black spiders appear at home
- Insects to feed on, such as cockroaches and flies. See cockroach control.
- Dark quiet corners and stored clutter.
- Cracks and openings around doors, windows and pipes.
- Wood, rubble and leaves piled at the building boundary.
Where they hide
- Dark corners, storerooms, under furniture and behind boxes.
- Piles of wood and stones in the garden.
- Abandoned shoes, gloves and tools.
- Meter openings and electrical boxes.
How to get rid of them and prevent a return
- Clean corners and storerooms with a vacuum and remove webs and eggs.
- Store items in closed boxes rather than cartons.
- Seal cracks and fit screens on windows and openings.
- Reduce the insects they feed on.
- Keep wood and rubble away from the wall, and wear gloves when moving neglected items.
For other types read house spiders: telling the dangerous ones apart.
If someone is bitten
- Go to the emergency room if symptoms are severe or the person is a child, elderly or has a chronic illness.
- Wash the bite with soap and water.
- Photograph the spider if safely possible.
- Do not rely on folk remedies or delay seeing a doctor.
Web-building spiders versus hunting spiders
- Web-builders: stay near their web in corners, under furniture and in storage rooms, waiting for insects, and rarely wander far from it.
- Hunting spiders: do not rely on a web. They roam at night and chase prey, and may be seen on walls and floors.
Knowing the difference decides the approach. The first is handled by removing the web and its spot, the second by sealing entry points and reducing the insects they feed on.
Where to look specifically for the dangerous type
- Piles of firewood, stones and rubbish in the garden and on the roof.
- Storage rooms and abandoned boxes, beneath cabinets and behind appliances.
- Inside shoes and gloves left lying around, in basins and on outdoor furniture.
- Dark, dry, rarely disturbed places that are seldom cleaned.
Wear thick gloves when moving things in these places, and do not put your hand into a crack or behind a pile without seeing what is there.
How to remove a web and egg sacs safely
- Wear gloves and use a long-handled broom or mop.
- Lift the web and the small white egg sacs in a single movement into a bag.
- Tie the bag firmly and dispose of it outside the house.
- Clean the spot with detergent and dry it. Watch for the web to return over the following days.
Do not crush the spider with a bare hand and do not press on egg sacs, which may burst in the room.
Why they keep coming back despite spraying
Spiders live on small insects, so if the insects are there (flies, mosquitoes, small cockroaches) the spiders will return to feed on them. Treating the insects that attract them, sealing cracks and removing piles and rubbish reduces spiders more than spraying alone, because a spray affects only what it touches.Is insecticide needed?
- Usually cleanliness, sealing entries and reducing insects are enough.
- If sightings repeat, treat corners and cracks with a product labelled for crawling insects according to the label, or use a licensed company.
- Avoid spraying children's sleeping areas or food surfaces.
FAQ
Does every black spider bite?
No. Most run away and bite only when grabbed or pressed.
Does a spider mean a dirty home?
Not necessarily, but it usually points to insects and neglected corners.
Summary
Most black spiders are harmless. Clean corners, seal entries, reduce insects, watch for the shiny type with a red mark, and see a doctor after any severe bite.
Spiders and Children: Simple Rules
Teach children not to touch any spider and not to put their hands in boxes, shoes and neglected piles. Shake out abandoned shoes and gloves before wearing them, and inspect toys stored outdoors or in storerooms before children play with them. If a child is bitten, treat the case seriously and go to the emergency department without waiting.
The Outdoor Surroundings and Garden
Spiders often enter from outside, so reduce piles of firewood, stones and rubble against walls, trim shrubs touching the building, and check electric meters and outdoor boxes carefully. Reducing strong lights on walls reduces attraction of the insects spiders feed on. Seasonal cleaning of courtyards and roofs prevents them being used as shelter.
Why Do Partial Solutions Fail?
Removing the web alone means it returns within days if the cause remains, which is an abundance of insects and neglected corners. Random spraying kills only what it touches and leaves egg sacs and hidden spiders. The integrated solution: periodic cleaning, sealing entries, reducing insects and removing clutter. If scorpions worry you, read the scorpions guide since they share some places.
Visit the Branch to Identify the Type
If you doubt the type, photograph the spider from a safe distance, or put it in a sealed container without touching it, and bring it to one of our branches and we will help identify it and guide you to the right product for your case and how to use it safely. Read the product label before application, and avoid spraying in children's sleeping areas or on food surfaces.