Why do most men belch out loud?

I know it's natural but it's gross and disgusting. I don't find that funny. I live in a house of men (my dad, two brothers and two male cousins) and I hear belching and they don't say excuse me. I don't see how it doesn't bother some people. I'm the only female in the house since mom left. It's like males took over. I can't wait to leave for college. I love them but I can't live in a house of men anymore. My dad said, "If I get married I'm going to have to get used to it. Go hang out with our aunt or friends if you wanna be with the ladies. When my aunt comes over, she always wants to take me somewhere so I won't be in the house with men all the time. She has been getting to spend the night. It isn't the same as having a mother.