There are a number of ways they are personified. One is that they are given voices and language. They get made or angry when they are taunted. And they are frustrated when the dwarves escape.
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Spiders, trolls and wood-elves
In chapter eight of the hobbit. Bilbo bagging's rescues the dwarfs. He's more brave then at the beginning of the book. He leads the spiders away to free the dwarves. When they return he kills many and they learn to fear his blade. He keeps the dwarves together and leads them out of the spiders area.
Bilbo rescues the dwarves after they were captured by the spiders. He cuts them down from the webs and distracts the spiders while the rest escape.
'The Hobbit' of course!
Tolkien's vast imagination.