Tag Archives: House Spider

The Mouse Spider, for those who are worried

A few people have been asking me about the Mouse Spider, following a scary story in the media this week about a British man who was bitten by one which had somehow climbed into his bathrobe. The man had an allergic reaction causing his back to swell up, and it was because of his own knowledge of spiders he was able to identify the spider as a Mouse Spider (Scotophaeus blackwalli). The media went into overdrive, some reporting that the Mouse Spider is a close relative of the deadly Australian Sydney Funnel-web spider. This is a mistake – there are a number of species of spider in Australia known as Mouse Spiders, and they are related to the Sydney Funnel-web, but they are no relation to the much smaller European Mouse Spider. Here is a photo I managed to take of the European Mouse Spider in May 2015 – I haven’t seen one since then:

The common name for this species comes from the fact it has mouse-coloured hair on its abdomen – it is nowhere near as large as a mouse, and, in fact, appears quite a bit smaller than the so-called Giant House Spider (Eratigena atrica) which terrifies so many people in the autumn, when big long-legged males enter houses cruising for females. Here is one of these harmless terrors I photographed a few weeks ago:

The Mouse Spider is a stocky, slow-moving spider which is native to Northern Europe, including the British Isles, and widespread but very rarely encountered by ordinary householders. It tends to like bark and stones to live under, and will wander around at night, hunting small invertebrates by sneaking up on them. The female has a reputation for biting if handled, but it is a shy species and definitely doesn’t go looking for trouble. The body of the female would be about as large as the body of a female Giant House Spider, but the legs are far shorter and it is, in many ways, more handsome. The bites are usually harmless although definitely noteworthy, but an allergic reaction is always possible with any creature capable of biting or stinging.

The best way of keeping spiders out of your house is to not leave doors open at night, in the morning or approaching darkness, and to check outside before opening windows. Also, do clean your home regularly to prevent them making themselves comfortable.

Spider Season Draws To A Close

I know a great many people will be glad to know large spider numbers will be returning to normal at last this autumn season. The mating season for House Spiders, Garden (Cross) Spiders and Steatoda nobilis False Widows is almost up. What this means is that the females won’t be releasing pheremones into the air to attract mates, so long-legged males won’t be running about the place and entering houses looking for love. For anyone afraid of those big spiders, then maybe you need to make friends with the thin, daddy-long-legs like Rafter Spiders (Pholcus phalangioides), aka Long-bodied Cellar Spiders, which live in houses and specialise in eating spiders:

A Long-bodied Cellar Spider eating a much larger House Spider which it has caught in a web. They will also happily eat False Widows... and anything else.
A Rafter Spider eating a much larger House Spider which it has caught in a web. They will also happily eat False Widows… and anything else.

Rafter Spiders seem to be a relatively recent arrival in Europe. In the Middle East they live in caves and produce the curtain-like webs normally seen in adventure movies. They are harmless to humans but their haphazard barely noticeable webs are considered a nuisance by housekeepers as they collect dust and easily collapse.

The method used by the spider to kill bigger spiders is amazing to watch. The Rafter Spider spots its prey at the other end of a room and carefully stalks towards it, usually walking upside down along the ceiling. It then gets into a pouncing position, pulling its body back against the tension of its long legs and then suddenly shooting forward to strike at a leg. The victim is paralysed almost immediately and falls, but is snatched by the predator before it can strike the ground.

A Rafter Spider with a Tripwire Spider, Segestria senoculata it has killed.
A Rafter Spider with a Tripwire Spider, Segestria senoculata it has killed.

The Last of the Big Spiders this year

I think many of you will be delighted to know that big spider season is ending soon. These big spiders which come into houses in autumn, are looking for mates. These unseen females are much stockier than their suitors, and generally stay in their webs, often hidden from pulic view. In order to let their boyfriends find them they release pheromones onto the air, and the males come running.

The biggest spider I have seen so far this season, a male Tegenaria duellica (sometimes called t. gigantea) House Spider. Just like all creatures confronted by an immense human monster, it fled and tried to climb the side of this old bath, in which I have grown potatoes.
The biggest spider I have seen so far this season, a male Tegenaria duellica (sometimes called T. gigantea) House Spider. Just like all creatures confronted by an immense human monster, it fled and tried to climb the side of this old bath, in which I have grown potatoes.

The males then live for a number of weeks or months in the webs with the females and leave before the young are born, or are killed and eaten for overstaying their welcomes. As a result, sensible males who leave early can grow to immense size and apparently live quite a few years. But by now most of the females have mats and will stop releasing pheromones and the males will go back to their regular lives, if they avoid the various predators that delight in eating them, especially Robins and Blackbirds, but Wrens too.