Millions of spiders have cast an eerie web over a Northland swamp, leaving their silky mark as they transport themselves around.
The countless baby arachnids have recently hatched, and are sending up a strand of silk which they used for "ballooning" around the Hikurangi Swamp, Northland Regional Council biosecurity officer Ross Johnson said.
"The tiny little spiders send up a silk, a gossamer, and they use it for ballooning - they get picked up in the wind and get blown around - otherwise the population density is too high in that one spot.
The silk was draped all around the swamp, but would disintegrate within a couple of days, Johnson said.
"Spiders have different types of silk they can produce, and this particular type used for ballooning breaks down very quickly - when it's dewed you won't see it anymore."
The phenomenon occurred every year within a couple of days of the money spiders popping out of their eggs, and was not necessarily related to recent flooding, Johnson said.
The maze of webs blankets hundreds of metres of road and stop bank edges around the swamp.
INTRIGUING WEB: The maze of webs blankets hundreds of metres of road and stop bank edges. Photo: SNPA