For the first time, researchers have captured literally every step of all eight legs using artificial intelligence.

Spider webs are beautiful and fascinating works of art. And although you probably meet them regularly in the forest, we actually know very little about how spiders build their webs. “The building phases of the web take many hours and consist of thousands of behavioral elements coordinated by a brain that is more than 100,000 times smaller than our own brain,” said Abel Corver in conversation with Scientias.nl. How does a spider with such a small brain manage to build beautiful, architectural masterpieces? Researchers figured it out.

Behavior of spiders

According to Corver, the way spiders build webs is fascinating; it has therefore aroused the interest of scientists for some time. “Thanks mainly to careful manual observations, we now know more about several behavioral elements,” Corver says. “Think of a variety of leg movements, such as walking, groping, and the way the spider forms the sidelines while building the web.” Yet much was still shrouded in mystery. “Before we started our research, it was impossible to fully map out how these different behavioral elements are combined by the spider during the different construction phases,” he explains. “Building a web takes many hours and consists of thousands of movements that follow each other in rapid succession. In addition, many spiders mainly build in the dark. This makes comprehensive manual analysis of this behavior largely impossible.”

Study

The researchers therefore decided to take a different approach in their study. “The goal of our research was to develop an automated methodology that can quantitatively visualize complex behavior using computer analytics,” Corver said. In order to follow step by step the building process of the beautiful spider’s web and to unravel the complex dance of the spider, the researchers first collected six orbweb spiders and placed them in a kind of arena, where infrared cameras and lamps were set up. Using machine vision software, specially designed to detect the movement of limbs, the team tracked the millions of leg movements of the spiders busy building a web.

This machine vision software made it much easier to understand how a spider weaves its web. “Even if you’re recording this on video, there are a lot of legs to follow over a long period of time,” Corver says. “It’s just too much work to look at each frame and annotate the leg points by hand. That’s why we have machine vision software developed that can detect the spin position frame by frame. That way we could document exactly what the legs do to build an entire web.”

Dance unraveled

It means that for the first time, researchers have literally captured every step of a spider’s eight legs as it builds its web, using artificial intelligence. And that gives us a unique insight into the complex, but beautiful technique. The most important discovery? The spiders all have a strikingly similar tactic. In fact, the way in which they build their webs is so similar that the researchers could tell in which construction phase the spider was just from the position of a leg.

spider brain

This interesting find also tells us more about what exactly goes on in the tiny spider’s brains. The fact that the spiders all follow the same rules when building a web confirms that those rules are encoded in their brains. “Despite the fact that in many cases the construction phases are carried out in a linear fashion, there are frequent occurrences of the spider interrupting the current construction phase and returning to a previous phase,” says Corver. “We wondered whether the rules of conduct might differ in these interrupted cases. However, our analysis shows that even in these cases, the building rules largely match.”

Our brains

According to the researcher, the findings also have important implications for ourselves. “Like building a spider’s web, much of our own behavior consists of sequences of behavioral elements,” explains Corver. “But we know relatively little about how networks of brain cells create these kinds of complex behavioral sequences. As neuroscientists we are often looking for specific types of brain cells, but it is easier to find a needle in a smaller haystack. Our spider species not only exhibits complex and potentially cognitive behavior, but builds these impressive constructs with more than 100,000 times fewer brain cells than our own brain. A better understanding of these brain mechanisms can serve as a building block for understanding similar mechanisms in other brains, including our own.”

The study offers new insight into how creatures with brains a fraction the size of humans can create elegant and complex structures with immense geometrical precision. “This study illustrates how recent advances in computer algorithms can provide new and detailed insights into complex animal behavior,” Corver concludes. “In addition, this research lays the foundation for our follow-up research.” In the forthcoming study, the researchers want to drug the spiders with mind-altering drugs to find out which circuits in the spider’s brain are responsible for the different stages of building a web. And possibly that will provide even more insight into the spider’s brain – and therefore possibly ours as well.