Especially longer and thinner ones.
I didn’t find a precise answer to the question, but I did find ‘Killer virus’ causes snakes to tie themselves up in knots | Metro News]this article which suggests that it’s just instinctual on their parts.
I imagine that a snake can feel when it’s getting itself tangled and can pretty easily correct for potential knots.
Just a guess: What we consider to be knots get to be that way when you take two parts of the string, and tighten it by pulling them in opposite directions. But that’s not how snakes move: Each part moves forward, so even if the snake is looped around itself in some complicated manner, it would end up simply moving out of its own way.
The simplest of knots, an overhand knot, would require that the snake crawl headfirst under a part of its body, something they don’t generally seem inclined to do.
Another vote for continual forward motion being a key factor.
Another issue is the difference in materials between string and snakes regarding flexibility and friction. String is pretty rough and doesn’t compress very well (just enough to get a snug fit in a knot, really). A snake, on the other hand, is quite smooth and is capable of changing the position and width of its body. So a snake that did get stuck in a knot would do the snaky equivalent of sucking in its gut, and that would loosen the knot.
Also, Darwinism. Snakes lacking the anti-tangle gene would have gone extinct years ago.
Not a snake, but hagfish intentionally knot themselves, using the contact to scrape off the copious slime they generate. I won’t post a link, due to the 2-click rule of oh-my-God-what-is-that-thing!?
Huh. And not just to scrape off the slime, but as an escape mechanism as well. It pushes the knot backwards to slide off something grabbing onto its tail.
I used to have regular access to several pythons, and was curious about this too. Royal pythons at least appear to be very uncomfortable in even a very loose overhand knot (I just tried gently encouraging the head through a large loop of body, nothing that could harm the snake). They would always back out immediately from any position that could lead to a knot, though they were normally happy to be moved around.
That’s a dramatic clip, wow.
Given how snakes crawl on each other in large nests, I’m guessing that’s not a natural problem, although at some point somebody must have tried tying a snake into a knot. Assuming there was no nerve damage or broken bones I would think a snake would be flexible enough to undo itself.
Related: Rat King. And sortof, Kilkenny cat.
It is my experience (no cite) that certain species of snake are more flexible than others of the same size. E.g. comparing a corn snake to a gopher snake.
I saw a snake tie itself during a school picnic, though it was in rather unnatural circumstances. A kid grabbed a black natrix type snake out of the local creek and held it up for all to see. The snake, probably terrified, thrashed a bit and tied its body in a knot, leading one of the teachers to accuse the kid of tying the snake. As I recall the snake did this twice. Then it unwound and the picnic ended and I think the kid tossed it back in the creek.
Exactly. A snake can of course loop itself in the form of a knot. However, for a knot to be tightened the ends must be pulled in opposite direction. A snake obviously can’t pull its head in one direction while pulling its tail in the opposite direction, and so the knot can’t be tightened to the extent it can’t be easily undone.
i’m going with yoga practice.
Hoop snakes slither up hills and then make themselves into a wheel and roll down. Or so I’ve heard.
My guess is that they teach snakes not to get themselves tied into knots in law school, where they learn loopholes instead. Or they shed their skin and get out of knots.