BALTIMORE, M.D. (WUTR/WFXV/WPNY) – Researchers at Johns Hopkins University took on a task to discover precisely how spiders build webs by using night vision and artificial intelligence to track and record every movement of all eight legs as spiders worked in the dark.
“I first got interested in this topic while I was out birding with my son,” said senior author Andrew Gordus, a behavioral biologist in the Department of Biology in the Krieger School of Arts and Sciences. “After seeing a spectacular web, I thought, ‘if you went to a zoo and saw a chimpanzee building this you’d think that’s one amazing and impressive chimpanzee.’ Well this is even more amazing because a spider’s brain is so tiny and I was frustrated that we didn’t know more about how this remarkable behavior occurs. Now we’ve defined the entire choreography for web building, which has never been done for any animal architecture at this fine of a resolution.”
Web-weaving spiders build their webs blindly using only the sense of touch. To observe the spiders while they build their webs at night, the lab designed an arena with infrared cameras and infrared lights. With this set-up, they monitored and recorded six spiders every night as they constructed their webs. The team tracked millions of individual leg actions with machine vision software designed specifically to detect limb movement. “Even if you video record it, that’s a lot of legs to track, over a long time, across many individuals,” said lead author Abel Corver, a graduate student studying web-making and neurophysiology. “It’s just too much to go through every frame and annotate the leg points by hand so we trained machine vision software to detect the posture of the spider, frame by frame, so we could document everything the legs do to build an entire web.”
After observing each of the spiders, they found that web-making behaviors are quite similar, so much so that the researchers were able to predict what part of a web a spider was working on just from seeing the position of their legs. “Even if the final structure is a little different, the rules they use to build the web are the same,” Gordus said. “They’re all using the same rules, which confirms the rules are encoded in their brains. Now we want to know how those rules are encoded at the level of neurons. Corver added, “The spider is fascinating because here you have an animal with a brain built on the same fundamental building blocks as our own, and this work could give us hints on how we can understand larger brain systems, including humans, and I think that’s very exciting”.