Spiders Identification Greenwich: What Signs Should You Look For?

Read the Web First

More practical than trying to identify a spider that has run under the sofa. Three web types cover almost everything found in a British building, and each one identifies its builder.

A flat sheet with a funnel or tube at one edge

The house spider. A dense horizontal sheet in a corner, behind furniture, under a cupboard or in a garage, with a tube retreat at one end where the spider waits. This is the web that produces most of the webbing people want cleared, and it is rebuilt readily.

A loose, untidy, three-dimensional tangle

A cellar spider or a false widow. Irregular strands with no obvious pattern, in a ceiling corner, a window reveal or a cellar. The cellar spider's version is very fine and messy; the false widow's is tougher and often has taut anchoring strands running down to a surface.

A neat wheel-shaped web

A garden orb weaver, and almost always outdoors - across a doorway, between plants, over a window. Rebuilt daily. Impressive and irrelevant to anything indoors.

The Four You Will Actually Find

House spider

What to look for: large, brown, hairy, long-legged and fast. The one in the bath in September. Builds sheet webs with a funnel retreat in sheds, garages, cellars and the quieter corners of houses.

What it means: nothing worrying. Harmless, and the most common spider in British buildings.

Cellar spider

What to look for: very long, extremely thin legs and a small pale body. Hangs upside down in a loose tangle web, usually in a ceiling corner. Vibrates rapidly in its web when disturbed.

What it means: a dry, undisturbed corner. Harmless, and it preys on other spiders, which is worth knowing before clearing them all out.

Wolf spider

What to look for: medium-sized, brown, patterned, and it does not build a web at all - it hunts across the ground. Usually seen running across a floor. Females sometimes carry an egg sac or young on the back.

What it means: it has wandered in from outside. Harmless, and since it builds no web it contributes nothing to a webbing problem.

Noble false widow

What to look for: a glossy, rounded, bulbous body, usually dark brown, sometimes with pale markings on the abdomen. Legs are reddish or orange-brown rather than dark. Builds a tough, untidy tangle web, often in a window reveal, a porch, a shed or a conservatory.

What it means: the one worth identifying properly. It is the British spider most likely to give a bite worth mentioning, though bites are uncommon and usually amount to a local reaction. It is also the most commonly misidentified - a great many photographs sent to us turn out to be house or cellar spiders.

Egg Sacs

What to look for: a pale, rounded silk parcel attached in or near a web, or carried by the spider. Size and texture vary by species.

What it tells you: that clearing the webs alone will be followed by a fresh generation from the same place. This is why any genuine treatment removes egg sacs as well as webbing - leaving them means the population re-establishes from exactly where it was.

Reading the Location

What Spiders Do Not Do

Worth listing, because it removes several worries people arrive with:

• They do not damage the building. No gnawing, no boring, no structural effect whatsoever.
• They do not contaminate food. They are predators of insects, not scavengers.
• They do not breed to plague numbers indoors. They are territorial and cannibalistic, which limits density in a way that insects are not limited.
• They do not come up the plughole. They fall into the bath and cannot climb out.

The Spiders You Will Not Find

Worth including, because a fair proportion of spider enquiries are driven by something somebody read rather than something they saw.

• There are no dangerous native spiders in Britain. No British species poses a serious threat to a healthy adult. The noble false widow is the one capable of a bite worth mentioning, and that amounts to a local reaction comparable to a wasp sting in most reported cases.
• Black widows do not live here. They are sometimes shown in articles about false widows, which is where a good deal of the alarm comes from.
• Tropical species arriving in fruit are vanishingly rare, and the ones that make the news make the news precisely because they are unusual.
• Nothing found in a British house lays eggs in skin, burrows into walls, or does any of the other things that circulate online.

If you have seen something that genuinely does not look like anything on this page, photograph it and send it. That is a reasonable thing to do and we would rather look than have somebody worrying about it.