The discovery of a massive nest of huntsman spiders on WA's south coast has given researchers a glimpse at how the arachnids live in large family groups.

Bush Heritage Australia ecologist Angela Sanders made the surprise find while inspecting timber habitat boxes installed in Monjebup, east of Albany, for pygmy possums.

While some boxes had become homes for possums, one box was full of dozens of huntsman spiders, all believed to belong to one family.

"On lifting the lids of some, we found many huntsman spiders of all sizes whizzing around inside," she said.

The social spider

While it may be an arachnophobe's worst nightmare, the discovery has shone a spotlight on the huntsman spider's social habits — unusual in the spider world.

"We now know that they're a species of huntsman that live together, normally under the bark of a tree," Dr Sanders said.

"In the restored area, tree bark is in short supply at present and they've found the wooden boxes suitable.

"A single adult female lays eggs and the successive generations of siblings help each other out and share prey items.

"This has several advantages for the spiders, including faster growth. They're also heavier and healthier."

The huntsman spiders are able to recognise relatives. ( Supplied: Angela Sanders )

The Department of Primary Industries and Regional Development lists 94 species of huntsman in WA.

Female huntsman spiders can grow up to 15cm and have strong maternal instincts.

Family affair for huntsman

Curtin University spider expert Leanda Mason said huntsman family connections were unusual in the spider world.

"This particular species is quite social," Dr Mason said.

"It's not common in spiders. Most spiders do look after their spiderlings [but only] until they're old enough to go out by themselves.

"The [huntsman] mother and her offspring will hang out. There's generally one reproductive female, [and] as the other females approach adulthood, they leave or get eaten."

Dr Mason said the spiders had the ability to recognise relatives.

"They know how to sense each other and know they're related," she said.

"They feel each other with their hairs — it's similar to what bees do with recognising kin."

The largest huntsman in the world, found in South-East Asia, can grow to a leg-span of 30cm.