Why can't spiders climb up glass?

My mum always catches them in a glass and they can’t get out, till she puts them outside. Why is this and can you tell me your source. Thanks y’all.

13 Comments

SkateRForeveR
on February 6th, 2012

To “cling”, they use little prickly hairs on their legs. These hairs then cling to other materials, giving them the ability to walk up walls and such. They can grasp virtually anything even if it has only the slightest bit of texture. Glass, However, is slippery and has absolutely no texture at all. They cannot cling to something as smooth as this. That is also why they get trapped in the bath tub.
MexicanMug
on February 6th, 2012

All they need is a tiny imperfection in the glass to climb up it.
Guineapig
on February 6th, 2012

Glass is too slippery and has almost no nooks and crannies where their legs can stick in.
BlindPoet
on February 6th, 2012

they cannot climb up glass because they think that they will fall throught it becasue it is so shiny i asked a guy i know that works a animal hospital and he is the manager and that is what he said, they cannot click to a surface like this with their legs and they are not able to climb up it.
Hopes this Helps
Good Luck
AgeingNature
on February 6th, 2012

Go look at this picture:

http://www.arachnology.org/Arachnology/P...

It shows a spider’s foot. Basically two little hooks. The spider needs to insert these hooks into microscopic cracks in the wall, ceiling, or glass to climb. Glass is so smooth that there are not enough little cracks for the spider to insert the hooks.

Hope this helps,
Lorax
Mayumi
on February 6th, 2012

If that’s what you think can you come round to mine and tell the one that’s climbing up the glass he’s in, that he can’t do that
BigBoy
on February 6th, 2012

Because they don’t have sticky feet like ants and flies. You can’t climb up glass for the same reason.
Gothicbunny
on February 6th, 2012

The surface of glass is too smooth for a spider get any grip with its legs. That’s my guestimation, so I can’t list a source. You can try Yahoo search or Wikipedia.
Kiss
on February 6th, 2012

coz there’s no friction…..the coefficient of frictin is v small nd as a result the spider wunt be able 2 hold on to it
PassionForDance
on February 6th, 2012

Unlike other critters who who have something akin to a suction cup on there toes, such as geckos and tree frogs, our secrete a sticky substance like mucous as is the case with slugs, snails, and Rosie (The Hut) O’Donnell, spiders utilize hook like projections that cling to rough or imperfect surfaces. Glass is to smooth for these hooks to find purchase.
Xfactor
on February 6th, 2012

They can climb up glass but with difficulty…their feet are adapted to walk on rough ground.
SimpleStripes
on February 6th, 2012

spiders cant climb glass because there feet are hooked..making them agile climbers..but glass is totally smooth so they cant hook on to climb
DNewcomer
on April 1st, 2011

I have been keeping tarantulas for 15 years and I can assure you they CAN climb up glass without any problem. They don’t seem to be inclined to do so most of the time however.