I think it is a very hard situation to have your child living with you that is legally an adult. Some kids think just as soon as their 18th birthday comes everything has changed over night. My younger cousin just turned 18 a little while back and was living at home until she went to college. She was still asking her mom if she could go do things and stuff like that. Her mom said you know you are 18 now, I really can't tell you what you can and can't do. She said I know, but I just don't want you to get upset with me. I want you to know where I am and what I'm doing. Which I think is the very respectful thing to do. I think you should talk with you son/daughter first before you just throw them out on the streets. Tell them that they are 18 and technically they can do what they want now, but there are still some limits while they are living under your roof. They should still tell you what they are doing and when they are going to be home just so you have some idea and don't worry. And just because you're legally an adult now doesn't mean that you don't have to have respect for your parents still. You actually should even more so now. I don't think they should have to ask you every move they make, but at least respect you in your own home. Of course you will have to come up with your own guidelines specific to your life and child. But I think you should give them some limits and talk to them about this and see how it goes first. Maybe a couple weeks? Then if nothing changes at all and you know they are just not going to have any respect for you and your home, then you can tell them they can't live there anymore. Maybe after getting out in the real world as an "adult" might not be quite as smooth as they think. Then just remember that it may just teach them a lesson, and they may be ready to come back and respect what you want. I know when I moved out and was on my own and paying my own bills and everything, I realized how easy I had it at my mom's.