What age would you kick you adult kids out of the nest?

So I grew up in a different kind of family then my husband. When my husband turned 18 he had a month to find his own place and leave. In his moms eyes he was a adult and now had to take care of himself.

My parents were different, they never made me feel unwelcome and even now that I’m married and have my own house, I still have my bedroom there and am welcome anytime to go back home.

How was it for you or how will it be for your children? Will you kick them out of the nest at a certain age or are them welcome to stay as long as they want or even forever?