Why Spiders Don't Stick to Their Own Webs
Go out into the garden early on a cool morning and you might find one: an orb web strung between two branches, every thread beaded with dew. It's one of the most beautiful things a small animal makes.
It's also a trap. The spiral running round and round the web is covered in tiny droplets of glue, several dozen of them on every millimetre of thread. A fly that blunders into it gets stuck, and the harder it struggles, the more threads it touches.
And yet the spider who built it runs across it without a second thought.
So why doesn't the spider get caught in its own trap? The answer people have repeated for more than a century is that spiders have oily feet. That turns out to be true, in a way. But it's only one part of the story.
Not all of it is sticky
The first part of the answer is in the design of the web itself.
An orb web is made from more than one kind of silk. The frame round the outside, and the spokes that run from the centre to the edge like the spokes of a bicycle wheel, are made of dry silk with no glue on it. Only the spiral that winds round and round between the spokes is sticky.
So a lot of the web is perfectly safe to walk on. It's a bit like a kitchen floor where only some of the tiles have been freshly painted. If you know which ones are wet, you can get around fine.
For a long time, that seemed like enough of an explanation. The spider just avoids the sticky bits.
But they do touch the glue
Except they don't avoid them. Not entirely.
In a study published in 2012, researchers from the University of Costa Rica and the Smithsonian Tropical Research Institute filmed orb-weaving spiders building their webs. What they saw was that spiders touch the sticky spiral constantly. While laying it down, a spider repeatedly pushes against the sticky lines with its legs. Not once or twice, but hundreds to thousands of times for every web it builds.
Another account of the research describes spiders sweeping their hind legs across the glue again and again during construction, and brushing their bodies against glue droplets while subduing prey. The idea that spiders simply skip over the sticky threads has been more or less discredited.
So they do touch the glue. A lot. The question is why they don't stay stuck to it.
Part two: hairy legs and careful moves
The Costa Rica team found two things going on in the spider's legs themselves.
The first is hair. A spider's legs are covered in dense hairs, which scientists call setae. On these spiders, the hairs are branched, and they have pointed tips. That arrangement does two useful things. It means far less of the leg actually comes into contact with the glue, because the glue touches the tips of hairs rather than a smooth surface. And it seems to let individual droplets of glue slide along the hairs and drip off the pointed ends, rather than gripping the leg.
The second is technique. Watching the film closely, the researchers saw the spiders moving their legs in ways that reduce the glue's grip, keeping contact to a minimum and avoiding pulling straight against the sticky line. Another summary of the work describes the spiders sweeping their legs across the capture threads at an angle that lessens the glue's effect.
So it isn't only what the legs are made of. It's how they're used.
Part three: the non-stick coating
Which brings us back to oily feet.
The idea goes back to the French naturalist Jean-Henri Fabre, more than a century ago. He noticed that orb-weaving spiders often ran their legs across their mouthparts, and suspected they were coating them with some kind of protective lubricant. He reported that after he washed spiders' legs with a solvent, many of them stuck.
That experiment has now been repeated in more careful conditions. Researchers at the Natural History Museum in Bern, Switzerland, tested spider legs against sticky threads. Legs that were untreated, or washed only in water, barely stuck. Legs that had been washed with an organic solvent, which would strip away an oily layer, seemed to be about twice as prone to sticking, according to one account of the study.
The Costa Rica team found something similar. When they washed spiders' legs with a solvent and water, the legs stuck more firmly to the glue than before.
So Fabre was onto something. Spiders do seem to have a surface layer on their legs that helps keep the glue off.
What's still uncertain
It's worth being clear about the limits here.
The studies describe a chemical, oily-seeming surface layer, and the Bern team called it organic. But exactly what it's made of isn't spelled out in the work described here.
And most of this work has been done on a handful of orb-weaving species. The Costa Rica team filmed two tropical species, for example. Other spiders, and other kinds of web, may use different combinations of tricks.
The two main studies also put the emphasis in slightly different places. The Bern team focused on the coating. The Costa Rica team argued that the earlier evidence for a coating had been weak, and that simply avoiding the glue couldn't explain how a spider survives pushing against it so often. In their view, hairs, footwork and a surface layer all play a part.
No single trick
So the honest answer to why spiders don't stick to their own webs isn't "oily feet". It's oily feet, plus hairy feet, plus clever feet, plus a web where most of the threads aren't sticky in the first place.
Take any one of those away and the spider would have a much harder time. Put them together, and you get an animal that can build a glue trap, walk all over it, and still let go.
Which, when you think about it, is the whole point. A web is only useful to a spider if it can catch everything except the spider.
Sources
R. D. Briceño and W. G. Eberhard, "Spiders avoid sticking to their webs: clever leg movements, branched drip-tip setae, and anti-adhesive surfaces", Naturwissenschaften (March 2012). https://doi.org/10.1007/s00114-012-0901-9 (abstract via ADS: https://ui.adsabs.harvard.edu/abs/2012NW.....99..337B; accessed 1 Nov 2026)
Phys.org, "Why spiders do not stick to their own sticky web sites" (March 2012). https://phys.org/news/2012-03-spiders-sticky-web-sites.html (accessed 1 Nov 2026)
Smithsonian Science, "Fancy footwork and non-stick leg coating helps spiders not stick to their own webs" (March 2012). https://smithsonianscience.org/2012/03/fancy-footwork-and-non-stick-leg-coating-helps-spiders-not-stick-to-their-own-webs/ (accessed 1 Nov 2026)
Popular Science, "FYI: Why Don't Spiders Get Trapped In Their Own Webs?" (December 2012). https://www.popsci.com/science/article/2012-12/fyi-why-dont-spiders-get-trapped-their-own-webs/ (accessed 1 Nov 2026)
Kropf et al., "An organic coating keeps orb-weaving spiders (Araneae, Araneoidea, Araneidae) from sticking to their own capture threads", Journal of Zoological Systematics and Evolutionary Research 50(1) (2012). https://doi.org/10.1111/j.1439-0469.2011.00648.x (described via Popular Science; not opened)
