I think some cats are just skittish and there is nothing you can do about it. I have one, Taffy, he is a big giant chicken. He has what we call his "hidey hole", which is underneath my daughter's skirted vanity table. It is his go to place when he is scared, like if he hears someone rip off a piece of tin foil, oh boy, look out, he is off! I have tried to get him used to it by doing this, when he is in the kitchen in the morning, I will rip the tin foil very slowly and say to him "see, it's ok, it won't hurt you", and this has actually helped him. He used to be terrified of plastic bags too, but I did the same thing, I let him see me and I shook them open gently so that he could see that it was just an empty bag and it wouldn't hurt him, and now he is hardly afraid of those at all. I make sure and talk to him when it is something that he is scared of, if I say "it's OK Taffy, it won't hurt you", he really does kind of look at me and doesn't bolt away. However, he is still afraid when we have company over and he will bolt to his hidey hole. Once someone has been over a few times and he sees that they are OK, he will eventually come out while they are here, but if it's a kid, forget it. My nephew comes over and you will not see Taffy the whole time, but in that case, I don't blame him.