I have a severe fear of heights. It is so bad that I get light headed when I climb on a ladder to clean the roof-gutters. I'm a real hoot at places like God's Window.
I also have an issue with rats and, to a lesser extent, mice.
Something that many people don't know is that there is a difference between not liking something, fearing something and having a phobia.
It works like this (and I'm doing this from memory, so don't sue me if I don't get it 100% correct, but the basic idea is sound):
1. Don't like. This is where you will avoid something because you prefer not to have anything to do with it. But when you do come across it, you know how to handle the situation in a calm manner.
Example: Don't like spiders. You see a spider and quickly kill it feeling a cold shivering down your spine.
2. Fear something. Same as above, except, you freak out instead of handle the situation calmly.
Example: You start screaming when you see a spider walking on your leg and somebody else need to come take care of the spider.
3. Phobia: You fear something so much, you would inconvenience yourself to avoid situations where you may come across your fear. When you have to face your fear, you freeze up entirely or become almost catatonic. A phobia is an irrational fear.
Example: You win a vacation in Jamaica, but you rather give the tickets away because you heard there are so huge mofo spiders there.