"You couldn't be an arachnophobe and do this job," he muses after ploughing through thousands of spider webs on his tractor while mowing between the rows of vines this week.

"It was as if the front of the tractor had been tightly wrapped in layers of [plastic] wrap," he says. "The accumulation of web had even covered all the radiator area so in order to get airflow I had to punch a hole in the web and peel it back like a thick plastic sheet." Heck.

"Since we stopped using herbicides in 2017, we've been getting more and more weeds growing under the vines where the insects and spiders seem to thrive, but this year is something else," he says. "It's phenomenal, they are everywhere, big ones, small ones."

Even though Graeme mows from the relative comfort of the tractor's cabin, this year he has resorted to wearing two shirts for extra protection, as the spiders, especially the little ones, still get in. "They seem harmless enough," he says.

However, Graeme isn't as welcoming to the "bigger spiders" which sometimes end up crawling on his windscreen. "There's no way I'd let those ones run over my hand," he laughs.

Despite the number of spiders he inadvertently displaces while mowing, Graeme isn't too concerned about their plight . "According to published research, which gives an estimate for the number of spiders per hectare of a healthy vineyard, we have about 60 million spiders living here at Shaw Vineyard."

Now, that's a lot of spiders.

Last week's exposé on the small rock found suspended in a spider web at Fairbairn Pines prompted a bulging mailbag with many readers describing similar observations at other locations.

Robin Westcott of Belconnen was mesmerised by a similar phenomenon that occurred several times at her parents' home near Tweed Heads.

"Behind their house they had a very large, spreading camphor laurel tree with a gravel path beneath it," she explains. "Each morning the first person down the path waved their arms (or for the more arachnophobic amongst us, a stick) to clear the webs.

"It was quite common to see pieces of gravel wafting above the ground in the breeze or sometimes small twigs or leaves which had been used as web anchors," she recalls.

Robin assumes that the webs must have dried out and shrunk, thus elevating the objects. "The height above ground seemed to depend on whether the "guyline" was perpendicular or part of several angled connections," she explains.

Closer to home, on his deck on the suburban edge of Canberra, Ian Ridgway admits he often enjoys a glass of wine while watching orb weaver spiders spin their "nightly trap of death". However, one morning he recently noticed a small rock suspended about 15cm from the ground by a single thread of web, gyrating gently in the breeze. "The rock was about 6cm in diameter and weighed about 50 to 100 grams," he explains.

Just like Robin, Ian assumes "the single thread was an anchor line, and that a change in atmospheric conditions overnight had contracted the line''.

Remarkably, John Malnar of Murrumbateman has witnessed the phenomenon not once, but twice. When he lived at his parents' house in Latham in the 1990s, every afternoon for a week or so he drove his car into the carport and heard a 'soft bang'.

At first John couldn't work out what was causing the noise, but on closer investigation at the end of the week he discovered that a spider had suspended a small rock, about the size of a marble, from its web attached to a nearby gum tree. ''It was just at the roof height of my car and when I parked, the top of the car would bump it," he explains

Then last week John walked into a spider web near his home, and guess what was at the end ... another rock. "I would have taken a photo but the web broke when I tried to lift [up] the rock, which was about half the size of a golf ball," he reports.

Did You Know? Several readers, including John Standen of Kaleen, asked just how strong spider web can be. According to Dr Andrew Walker of the University of Queensland who was recently awarded a PhD for his research into insect silk, "spider silk is super strong, and orb weavers are among the strongest". The strongest silk's tensile strength is similar to that of steel (for the same cross-sectional area) but is around fifty times lighter. So for strands of the same mass, silks are much stronger than steel." Isn't nature amazing.

On a recent camping trip on the main range in The Snowies, Brad Poile of Collector was struck by this silhouette of a granite rock which he reckons "looks a fair bit like an elephant".

It's almost as eye-catching as this wooden specimen spotted on the lower slopes of Mt Majura about 10 years ago by Jennie Gilchrist of Chifley who thought the freshly trimmed tree "looked like a baby elephant climbing on the back of its mother". I wonder if it's still there?

The curious concept of 'dancing rocks' featured in last week's column prompted a flurry of correspondence about unusual geological properties of some rocks.

Colin Smeal of Holder recalls the extraordinary bouncing rocks his brother, Rex, showed him while visiting Cape Tribulation in Queensland in 1974.

"We stopped at a small beach that was covered in smooth round black rocks," reports Colin. "Rex, who had helped build the then new road to the cape explained that the rocks defied nature. He said if you threw a stone in the air that it would often bounce higher on the second bounce. Of course I said that was simply not possible. But to my amazement that's exactly what happened.

"Instead of bouncing with ever decreasing height, theses rocks miraculously bounced in varying ways with subsequent bounces sometimes higher or longer than the first bounce - impossibly defying the physical laws of gravity," explains Colin.

While Colin can't recall the exact location of the beach, your akubra-clad columnist suspects it may have been Thorntons Beach, made famous after featuring in an episode of the Leyland Brothers and subsequently declared sacred to the Kuku Yalanji Aboriginal People. Scientific information as to why the stones behave in this way is hard to find. Someone must know.

Fairbairn's 'dancing rocks' reminded several readers of the 'sailing stones' of Death Valley National Park in California where for many years, people were baffled by the appearance of long (up to several hundred metres) snail-like tracks that occasionally appeared behind large (15-45cm in diameter) rocks along the valley floor. The fact that no one actually observed the rocks moving led to all sorts of outlandish theories as to how they were able to move, including some sort of localised magnetic effect. However, a study in 2014 showed the tracks are likely created by wind pushing the rocks along on a thin layer of thawing ice. Now, I'd like to see that!

Clue: 1836

Degree of difficulty: Medium

Last week: Congratulations to Steve Leahy of Macquarie who was first to correctly identify last week's photo as an old piano outside the cafe on the corner of McEwan Avenue and Railway Street in Oaks Estate.

Meanwhile, more information has come to light regarding the 'ghost' service station at Bodalla featured in this quiz on February 6. "It was owned by Freddie Constable who was a carrier of goods to and from Sydney," reports David Elliston. "His yard was behind the service station building and you can make out his name, F E Constable, on the building.''

How to enter: Email your guess along with your name and suburb to tym@iinet.net.au. The first email sent after 10am, Saturday February 20, 2021, wins a double pass to Dendy, the Home of Quality Cinema.

When Peter O'Neill recently hiked up a seldom-walked, steep track on the Tidbinbilla Range, he was surprised by what he found near the summit.

"Not far from the top of where the vista of the beautiful valley opened up below me, I came across a two-person wooden seat resplendent with cushions," he exclaims.

"I would just like to thank the person(s) who carried it up there as I had the most relaxing morning tea with the best view," he reports. "And to top it off, a lyrebird decided to go through its song repertoire not ten metres from me." Got to love the bush capital.

CONTACT TIM: Email: tym@iinet.net.au or Twitter: @TimYowie or write c/- The Canberra Times, 9 Pirie St, Fyshwick