While in webs, why do spiders do spiders start to shake when provoked? Any clarification to this?

Question

Example: While outside on my front porch, i noticed a spider web, and the spider was in the web waiting for its prey. I breathed on the spider and starting shaking as if i took a deep breathe let all my air out(It started shaking uncontrollably). Is this some sort of defense mechanism the spider has? As a zoology major, i still have not found the answer to this question.

Answer 1

though spiders hav 8 eyes they hav poor eyesight,so they depend on hair covering their whole body 2 sense vibration.wit the help of these hairs they can sense vibrations in the air,in their webs or the ground.......so when u breathed on it the hairs felt da vibration in the air,& most probably da spider thought sum sort of animal was abt 2 attak it & it started 2 act weird......

Answer 2

Did the web move? Maybe your breathing made the web move I dont know. But if the spider was shaking that is pretty interesting. Maybe your hot breath changed its external temp to quickly and it started convulsing?

Answer 3

This is an instinctual defense mechanism for many web weavers.  Against animals with poorer vision, the spider just looks like a blur and the potential attacker can't see whats going on, and usually retreats.

Answer 4

I think it's rather the movement of the web that causes the spider to shake. I don't think your everyday spider has the strength to actually start shaking a whole web on it's own.