So why do we see more spiders in our houses come late summer and early autumn? 

The simple answer is sex.

Males of many species have now reached maturity and are on the hunt for a mate. It is these amorous arthropods that you'll see scuttling across your carpet of an evening in search of a willing partner. 

The attractive warm dry environment of our homes - coupled with the tendency to keep windows open as the weather is still relatively mild - means that we see an influx of spiders in our houses at this time of year. Some species live alongside us in our homes year round, we are just more likely to notice them now, as they seek out mates and reproduce.

Love is in the air

Female spiders are usually quite a bit larger than males, but reach sexual maturity slightly later in the year. Eager males set out in early autumn to find a mate, ensuring that they are ready and waiting when the ladies make an appearance.

When he finds a partner, a male will approach and wait to be accepted, before joining her on her web and mating repeatedly. Once he's done his thing, he'll die as winter approaches (in some spider species cannibalism is not unusual, with larger females eating their mates after copulation).

The female spider will then overwinter, before feeding on early insects the following spring and laying her eggs. She may live well into the year.

Which species are you most likely to see?

The spiders that you encounter in your home are usually one of four species.

House spiders (Eratigena or Tegenaria species)

These are the familiar large, hairy spiders sometimes seen running across your floor at night. There are several different species of house spider, which are tricky to tell apart! They’re all large and brown with very long legs, and spin sheets of webs in out-of-the-way corners.

Cellar spider (Pholcus phalangioides)

These thin, gangly spiders are also likely to be familiar. Also known as daddy long-legs spiders, they often make webs in corners where walls meet the ceiling. They spend most of the day sat very still, but if disturbed they have two very different reactions. Some curl up into a ball and try to be invisible, but others vibrate manically in an attempt to frighten you off. They’re superb predators and eat other spiders, including their siblings!

Mouse spider (Scotophaeus blackwalli)

These spiders get their name from the covering of tiny grey hairs on their abdomen (the rear part of the body), which looks a bit like mouse fur. The front of their body and legs are browner. They’re often found in houses and gardens, where they mostly hunt at night. Instead of making a web, they wander around looking for small insects to ambush.

Spitting spider (Scytodes thoracica)

These small spiders are often found in houses in the south of England, though are rarer further north. They’re straw-coloured with black flecks all over the body and legs. They come out at night to hunt insects. When they find a target, they spray it with a sticky fluid that glues their prey to the floor, making it easier for this slow-moving spider to approach safely.

Noble false widow spider (Steatoda nobilis)

These are the spiders that get most of the bad press. Noble false widows aren’t native to the UK, but have been here for over a century, slowly spreading northwards from the south coast. They’re dark brown with cream markings on their abdomen. They make messy webs in corners, like a house spider. Although they can bite, they are not aggressive and are only likely to do so if roughly handled. In the rare confirmed cases where a noble false widow has bitten someone, the bite has been compared to a wasp sting.

What about garden spiders?

The beautiful orb-weaver spiders that you see spinning intricate webs in the garden in early autumn tend to stay outside.

Garden spiders are the most common orb web spider in the UK often found in gardens, giving them their name! They are greyish-brown with a white cross on their back and spin their famous spiral webs! They sit in the middle of the web waiting to feel the vibrations of a struggling insect in the sticky threads of its web. They then rush out and wrap their prey tightly in silk to stop them from moving – finishing the job with a venomous bite! This may sound scary – but they are completely harmless to humans!

Live and let live

The truth is spiders live alongside us all year round and this is something to celebrate, not fear. These amazing animals are a vital part of our ecosystems, feeding on an astounding number of insects. It's estimated that across the world, spiders eat between 400 and 800 million tons of insects and other invertebrates a year. Many of the insects they eat are considered pests of food crops and garden plants.

So if you can cope with them, spiders are quite useful to have around the home. They will capture and eat insect pests and generally keep out of the way, preferring the quiet life in a dark corner. Spiders were around long before us after all. It's not their fault we've provided them with a warm, dry comfortable habitat!

The fear of spiders often comes from worries about being bitten, fuelled by urban legends and hyped-up headlines. In reality, very few spiders in the UK are even capable of biting a person, and the small number that can rarely do. So, the next time you spot a spider sheltering in the corner of a room, give it a wave and say keep up the good work!