"Teaches them to grow up and fend for themselves"
I know how fast they grow up, how do get them to grow out (of the house)
How do you get em to do that Vernee?
I need advice...

Converting their bedroom to your office would be one way to do it!!! That worked for me! Just kidding (but it did help)!!!
Actually, do you want to know the God's honest truth? What worked for getting the two older ones out of the house was having the two younger ones! After they both moved away to college, when they come back home, the 5yo and 7yo are so excited to see them and won't leave them alone. They won't let them go out of their site. So it grates on their nerves. And I don't really do anything about it either! Why? Great birth control!! I figure that if the oldest two see how much work the two youngest ones are, they'll be a little more cautious over the next few years! Now, mind you, that it drives me crazy too while all four are here because it sends the little ones into a tailspin! I have to send the older ones out for errands and stuff just to get some peace and quiet. The youngest two are gems while they're here alone. As soon as the big brothers show up, they are fighting for their attention and it's constant chaos until they leave! After 48 hours, they are ready to go back to school!! (And so am I!)
If you don't have younger ones, I'd borrow a few screaming toddlers a few days a week! Or you could always resort to making them pay rent or a 10pm curfew!