Science

It’s Really Raining Spiders In Australia

It’s raining angel hair in many parts of New South Wales Australia…or at least angel hair spider webs left over from the migration of millions of baby spiders.

It's Really Raining Spiders In Australia

More on Australian spider migration and angel hair webs

Naturalist Martyn Robinson from the Australian Museum explained to the Sydney Morning Herald that in the spring baby spiders that release a thin streamer of silk web into the wind that can sometimes travel long distances. He notes that these spiders frequently travel in large groups and their skeins of angel hair webs eventually fall to the ground.

Robinson says the dispersal technique is called “ballooning”, and is typically used by baby spiders. The spider climbs to the top of a tree or tall bush and and releases a streamer of silk that catches in the wind and carries the spider aloft.

It’s possible for spiders to travel for hundreds of kilometers and up to three kilometers above the ground as they are blown by the wind, Robinson noted.

“They can literally travel for kilometres … which is why every continent has spiders. Even in Antarctica they regularly turn up but just die,” he continued. “That’s also why the first land animals to arrive on new islands formed by volcanic activity are usually spiders.”

In years with high spider births, the mass migration of baby spiders can result in “entire fields and paddocks and trees festooned with this gossamer or Angel Hair, as some people call it,” Robinson pointed out.

The official name for angel hair is gossamer, which is a non-adhesive silk that snags easily, and is one of nine separate types of silks different species of spiders can produce.

Angel hair is also often found after heavy rains or floods.

“When the ground gets waterlogged, the spiders that live either on the surface of the ground or in burrows in the ground, come up into the foliage to avoid drowning,” Robinson explained.

When water shows up, these ground spiders spin silk “snag lines” straight up into the air until they catch on a bush or tree branch, and then pull themselves up out of the water.

The Angel Hair effect can be seen frequently after floods, because large numbers of spiders are using the same silk “roads” to get away.

“Everywhere a spider goes it leaves a trail of silk … so if they use somebody else’s silk line, they put their silk line over that,” Robinson said. “You end up with thick silk roads … criss-crossing finer silk lines to produce this interwoven shroud.”

Statement from local resident

A resident of the town of Goulborn in New south Wales, Ian Watson commented that his house looked like it had been “abandoned and taken over by spiders”.

“The whole place was covered in these little black spiderlings and when I looked up at the sun it was like this tunnel of webs going up for a couple of hundred meters into the sky.”

“It was beautiful”, he added. “But at the same time I was annoyed because … you couldn’t go out without getting spider webs on you. And I’ve got a beard as well, so they kept getting in my beard.”