More exercise works for many creatures...and besides hormones, many snakes (in my experience) are drawn to fresh air coming into their cage IF you have
the sort of cage with limited airflow. Just look at how much information IS in the air for them to 'read'...it's no wonder. It's their best sense.
I can't speak for boas, as I only had a solo female who never pushed (thankfully, as she was big & strong), but maybe it's boredom & a need for motion too?