A baffled Queensland man has stumbled upon a group of "pinky-red balls" while taking his dog for a walk in Ipswich.
The Gold Coast man said the strange ball-like clumps appeared randomly scattered across a footpath.
"Something I’ve never seen before," he said on Facebook on Tuesday alongside two photos.
"While walking the dog by the creek I noticed all these pinky-red balls," he added, wondering what they could be.
The post garnered thousands of comments from curious Aussies who were equally shocked and amazed by the discovery.
Some thought the weird find "looked like brains," while others suggested "meatballs" or "fish food" as a joke.
"How's the weather mate? Yeah bit cloudy with a chance of meatballs," one quipped, a nod to the family-friendly movie bearing the same name.
'Amazing' mystery solved
Upon closer inspection, the man revealed the clumps are actually clusters of worms.
Some suggested sludge worms — also known as Tubifex worms — while others said they could be blood worms.
Georgina Binns, from the School for Natural Sciences at Macquarie University, confirmed they are in fact earthworms, but called their behaviour "strange".
"When it rains, we see earthworms move to the top layer of soil, and will even escape from the soil altogether when the soil is saturated," she explained to Yahoo News Australia.
"They 'ball up' when they are trying to avoid unfavourable conditions, such as increased soil acidity, cold temperatures or too much water, to avoid as much contact with their environment as possible."
Ms Binns explained that earthworms secrete mucus to help them move through tight soil easily. The lubrication also helps them hold on to their partner while mating.
"I think what we're seeing in these balls, is extra mucous to help bind them together but to also help with water resistance in those saturated ground areas," she said, adding it's an "effective strategy for survival."
However, Ms Binns said "it's rare to see so many balls of worms".
"Captive worms farms might experience a 'worm ball' due to lack of caring for them properly. But they should be happily eating soil mostly alone underneath," she added.
The heavy rainfall in Queensland this week, and in recent months, is likely driving the worms above ground as the earth has become saturated.
"They ball up in groups for protection," Ms Binns said of earthworms, who don't take well to water.
'Desperately trying to survive'
Some social media users familiar with worm behaviour expressed concern for the wrigglers.
"Poor things, they need dry soil," one person said.
"Ground too wet, they need to breathe," explained another.
One said it's "very cool" to see the worms in survival mode.
"That's so sad, they are desperately trying to survive and get out of the water," another posted.
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