Why doesn't a spider get stuck in its own web?

spiders don't come into contact with their webs all at once. Instead, they move nimbly along the strands of their webs with only the hairs on the tips of their legs making contact with the sticky threads.  

One hypothesis, that spiders simply skip over the sticky threads, has been more or less discredited. In fact, orb-weavers sweep their hind legs across the goo hundreds or thousands of times as they make their webs. They also brush their bodies against the drops while they're subduing prey. Hope I helped

glacial erosion, the picking up and movement of earth beneath a glacier, is also referred to as plucking. erosion and transportation of individual pieces of bedrock, especially large "joint block occur as a result of this glacial erosion. plucking is type of erosion in which rocks become frozen into the bottom and sides of the glacier.as the glacier moves downhill it 'plucks' the rocks frozen into the glacier from the ground.