A carpet of brown greeted Matt Lovenfosse as he pulled up to his home on Monday morning. “So I went out to have a look and it was millions of spiders,” he says.
They were running ahead of flood water rising up from Kinchela Creek, pouring across the back of Lovenfosse’s property on the mid-north coast of New South Wales.
“It’s amazing. It’s crazy,” he told Guardian Australia. “The spiders all crawled up on to the house, on to fences and whatever they can get on to.”
The spiders aren’t the only animals he has spotted fleeing the floods. “When the water goes up, the snakes go up into the trees,” Lovenfosse said.
As record-breaking rains batter the NSW coastline and southern Queensland, causing widespread flooding, animals and insects are scrambling to escape the waters.
Shenae and Steve Varley witnessed a similar phenomenon on Sunday, when they visited the Penrith weir in western Sydney. Shenae said spiders covered “the entire length of the railing that’s not under water”.
“There were also skinks, ants, basically every insect, crickets – all just trying to get away from the flood waters. My husband videoed it, because I was not going close to it. When he was standing still he had spiders climbing up his legs. A skink used him as a pole to get away from the water.
“Penrith floods quite regularly, and this is not something I’ve ever thought about before,” she said.
Macksville resident Melanie Williams was also shocked by a swarm of spiders climbing the outer wall of her home as they fled for higher ground. “I occasionally see spiders around the place but never anything like that, it was just insane,” she told the ABC.
The spiders outside her home were “horrific” but her neighbour told her there were twice as many inside his garage, she told Guardian Australia.
Lovenfosse said he had witnessed the same phenomenon in a flood 20 years ago this month, when he was seven.
Dr Lizzy Lowe, an arachnologist at the independent research company Cesar Australia, said it was common for swarms of spiders to appear during floods, but only at certain times of year.
“In spring and summer it’s peak spider time. Many will die off in the winter, or survive as egg sacks … If you get floods in summer you’ll see lots of spiders.
“There’s no more spiders than would be there usually,” she said. “You’re just seeing more of them. Most of the spiders that you’re seeing … are ground-dwelling spiders.
Lowe urged people who came into contact with spiders to exercise empathy, even if they were scared.
“These are native species trying to do their thing, trying to survive. The last thing that you want to do is get out the insecticide spray.”
The spiders would be “doing their best to disperse” as soon as the flood waters went down, she said. “They’re not going to be doing anyone any harm.”
Williams stressed the importance of spiders to the ecosystem. “They’re very, very good insect hunters, so if you got rid of all the spiders you would be plagued by insects. We should be worrying about saving the spiders as much as we’re worried about saving the koalas.”
People would be happy if the rain helped end NSW’s ongoing mouse plague, but experts say that is uncertain.
“It’s a bit of a tough one to predict,” a CSIRO research officer, Steve Henry, said.
“Certainly areas west of the divide are not getting nearly the same amount of rain as places to the east are getting. Unless we’re getting rainfall of a magnitude that will fill the [mice] burrows with water, we don’t think it will have a significant effect.”
For example, the 86mm of rain reported over the weekend at Gilgandra was a good fall but “unless it’s enough rain to flood out burrows, they’re just going to hunker down, wait for the rain to pass and be back in business”.
Rain would “make conditions less favourable for mice”, Henry said, but “whether this is the precursor [to the end of the plague] is uncertain, unfortunately.”
When floods did kill off mice, it usually happened quickly. “Farmers talk about the mice disappearing virtually overnight,” the research officer said. “They get to such high numbers they become quite stressed … they start to run out of food, which facilitates the spread of disease, they start eating the sick ones, they turn on the babies, and then it’s all over. It’s quite a grizzly story.”