It's that time of year, the gentle sounds of summer approaching, lawnmowers, crickets, birdsong, the fizz of beer cans opening, and the shrieks of suburbanites confronted by rain spiders.

"They are among the biggest non-tarantula spiders in the world," said amateur arachnologist Astri Leroy, of the fat-bodied long-legged Sparassidae often found indoors in the last parched weeks before the summer rains come.

Nestled behind alarm sensors, they set off burglar alarms when stepping out for a nibble on a passing insect, and plunge households into turmoil through arguments over who is going to remove them, reducing strapping alpha males into Tupperware-clutching wrecks.

"None of the ones I know do any harm at all, but they are pretty big," said Leroy, a founder member of the Spider Club of Southern Africa.

They can have a legspan of up to 7cm and a head to abdomen measurement of about 3cm. They are spread from Cape Town in the south to Kosi Bay in the north and appear to like bushed areas with grass and gardens. They like to live among leaves and take two to three years to grow to adults, with the female fatter than the male, who is brighter with longer legs.

The males are slightly mottled, and the females a grey brown with dull yellow and black stripes under their front legs.

As nocturnal hunting spiders, they do not make webs and tend to hunt in the garden.

They can bungee down from the ceiling, but as they are heavy they prefer to run along the walls.

"They wander inside for insects that flap around the house after we have switched the light off, they find this very interesting, it is nothing malicious," said Leroy.

They also do not like being outside in the rain and are seen as a sign of approaching rainfall.

They sleep during the day but cannot close their eyes.

"We mostly have pale coloured walls, so we see a blob curled up on the walls, or hiding in the curtain."

When they are ready to lay eggs they go outside and build their egg cases out of silk, but occasionally they are trapped indoors and build their nests out of shreds of tissue.

The egg cases are guarded by the mother spider and, said Leroy, exhalation by a human inspecting the spiderlings, can bring the mother out to protect them.

"She comes out with her front legs out and it looks scary. I have been bitten by them but it was like a pinprick," Leroy said.

"It is a very scary thing to happen, I still jump and shriek."

The spiders are believed to be harmless to humans, saving their energy instead to catch their feast of insects, among their favourites, the Parktown prawn.

According to "Iziko Museums of Cape Town", guinea-pigs bitten by the spider died within three minutes, but this was found to have been from shock and not the effects of any venom.

The website said they are often confused with baboon spiders which are fatter and hairy.

To remove it from the home, Leroy says the brave can coax it out of a window with a feather duster, but it could run towards your arm.

Otherwise invert an empty coffee jar over it, slide a piece of paper underneath and carry it off.

To discourage rain spiders from entering the house, spray windows, doors and bricks with an insect spray or citronella.

"Teach your children to react slowly around it," said Leroy, who believed this would encourage children to become interested and not just squash them on sight.

For further information, Leroy can be reached on [email protected]

* Wits University will host this year's Yebo Gogga Yebo AmaBlomo bug and flower show from October 5 to 9 with the theme "Survivor". - Sapa