I would say, Simile because this compares the feeling of seeing the machine to being stabbed by a dozen awls. Similes use like or as to compare two different objects, so that is what leads me to believe this. It cannot be a symbol, because that does not represent anything. It cannot be personification because it does not take a nonliving object and give it human features. I would say that's it a metaphor, but it uses as, so I firmly believe that it is a simile..
It would be a good idea because due to them living in normal house hood areas it can cause harm to them and maybe even harm near by local animals that were supposed to be there which further shows that they should be relocated.
