Alex isn't limited by normal boundaries, like gravity. He likes to climb out of his second story window, which is why his window has been adjusted so that it only opens a few inches now (because his room needs the airflow, we can't seal the window entirely).
Every year, various neighbours stop by our home to let us know that Alex's leg is dangling out his window. We usually get 4-6 visits throughout the summer. Last night was the first one for this year.
It's frustrating and a little frightening. And it's really difficult to manage behaviourally. Once he's got his leg out the window, he's achieved what he wants. All we can do is tack negative consequences on it, so that it's not worth it. So when he takes the screen out of the window, he loses toys for the evening. But as the evidence shows, that's not always enough.
Alex has no sense of personal safety when he wants something. He'll run across the street without checking for traffic. He'll walk away from school or home without an adult. I've caught him trying to balance on any number of balconies (the 6th floor of the Museum of Nature remains his most terrifying attempt). The concept of "you could get hurt and are freaking people out" is too complex to convey to him, so we have to stick with "don't do this or you'll get in trouble" which we all know really translates to "don't get caught."
These are the sorts of things which exhaust parents of special needs kids. It doesn't happen often enough to have automatic responses in place and be a part of the routine. We have to be vigilant for long periods of time where it's not happening and then still be prepared to act quickly once it does. Humans aren't very good at that (attention-fatigue is one of the biggest challenges for guards, soldiers and police officers).
We'll just have to keep on as we're doing and hope it doesn't get any worse.