Some snakes absolutely do indicate that they want out of their enclosure by hanging out at the front and/or 'pacing' near the front. I have a few that will climb right out onto my hands when they want out. As others mentioned, this varies based on the individual snake's temperament, how habituated it is to you, and any previous experience with interaction and training.
It's really quite surprising how interactive some (NOT all) snakes can become given the right type of interaction. I use a lot of what's called 'choice based handling' and have gotten very striking results. Linking a video below by my snake training mentor, Lori Torrini, which you might find interesting.
https://www.youtube.com/watch?v=4ljt...el=LoriTorrini