In 2013, the internet was introduced to tiny, bizarre structures called "silkhenges", photographed in the Amazon jungle of Peru. Even experts puzzled over what could have made these mysterious little monuments, which looked like circular picket fences, only a couple of centimetres across. Then, later that year, entomologist Phil Torres and his colleagues brought us the answer: they discovered baby spiders hatching out of them.

The mystery was (partially) solved, but it wasn't until now that you could watch these adorable spiderlings emerging from their picket-fenced nursery.

The new silkhenge footage was taken not in Peru, but Ecuador, where Torres visited Yasuni National Park accompanied by biologist Aaron Pomerantz. "We weren’t specifically looking for these in Ecuador, which made finding them so much more exciting," Pomerantz tells Earth Touch.

"Aaron was the one who first spotted this while we were out," adds Torres. "I think their range is much bigger and they are much more common than we think, we just need more eyes looking for them all across South America."

The scientists suspect the "silkhenge" structures may protect the eggs by keeping out water, or perhaps ward off parasites or predators. Image: Phil Torres

In the video, the scientists' excitement is palpable as they watch the itsy-bitsy wonders – each roughly the size of a grain of salt! – emerge into the world. Every other observed silkhenge hatching has seen only one newborn, but the researchers were delighted to find this one contained triplets.

"It was surreal to watch them hatch," Torres says. "We have communally spent so many hours looking for these things … finally, those hours paid off."

However, still more mysteries surround silkhenge. For one thing, the scientists don't know what kind of spider this is. DNA testing didn't match any known species (of course, not all known species have had their DNA sequenced), and baby spiders are difficult to identify by appearance, so the researchers' next big task is to catch an adult in the act of building a nest.

"It's so cool to be in the process of a discovery," Pomerantz adds. "And this is just one of literally thousands of unsolved biological mysteries out there in the Amazon."

The duo also aren't yet sure what the structure's purpose is. Pomerantz suspects it may protect the eggs by keeping out water, or perhaps its function is to ward off parasites or predators, though more observation and some experimentation will be needed to confirm this.