This morning while in the bathroom I noticed a spider in the bath, I duly rescued it and set it free, but a question came into my mind.
The spider was perfectly able to walk horizontally on the plastic bath, but struggled beyond a certain angle when trying to climb the curved surface.
I’m not really familiar with how spiders grip surfaces, but my question is what is the maximum angle of slope that a spider can climb on a smooth surface?
Does it depend on the coefficient of friction of the surface and the mass and size of the spider? What other limiting factors are there for climbing slippery surfaces?
Some spiders are able to climb smooth surfaces that are vertical easily, many of my tarantulas do. I would say that it would depend greatly on the spider species, family or subfamily: different spiders are built to do different things.
Size has no influence, I am a witness of this. I have tarantulas that are quite small at 1/4" (babies) and some large adults in the 7-8" legspan, both can climb the walls of their glass tanks easily.
From what I know, it is because of how the ends of their legs are made. They form a type of suction that lets them grip to almost perfectly smooth surfaces. For climbing more rugged terrain they use a tiny claw that their legs are also equipped with.
I can’t speak much about other species as most of my spider knowledge is about tarantulas.
Do they climb the glass “bare-legged”? I once looked into keeping a tarantula, and the pet store lady warned me that they tended to spray a fine net of webbing on the walls of their tank, and use that for purchase to climb the wall and escape through the top.
Do they climb the glass “bare-legged”? I once looked into keeping a tarantula, and the pet store lady warned me that they tended to spray a fine net of webbing on the walls of their tank, and use that for purchase to climb the wall and escape through the top.
Yes, they can climb glass “bare-legged”. Tarantulas don’t spray their silk webbing, they lay it down while walking with their spinerets (which are located at the rear of their abdomen).
Laying some silk does help them climb the glass better in the future but they have to climb it bare first to lay down the first strands. Also, different species have different webbing tendencies. Those who lay the most are usually arboreal and use it as a means to build their hideaways in the trees or brush, they use silk as a building structure and also as a way to stop others from seeing them. My ground dwelling species are the ones that lay the least silk (not visible with regular lighting and not on the glass that I’ve seen) and is used to help them hunt prey through vibrations. They still climb the glass with ease though!
Now what can be stressful about a tarantula walking up the sides of the glass is if it gets it’s claw stuck while walking upside down on the mesh cover of the tank. This has happened a few times to me with a couple of my tarantulas and at first used to freak the crap outta me. Picture trying to help a dangling tarantula that is freaking out without having a heart attack!
