Thats a pretty vague catch-all-statement. There is incredible variability in the activity of different animals depending on barometric pressure, weather patterns, light and dark conditions, new scents in the home etc. impossible to compare the habits of different animals across the country. I've had bps that NEVER leave their hides unless they are eating, drinking or defecating, and have also had bps that were very active, with the exact same husbandry.
As for falling, I wouldn't worry about it. These guys are much tougher than you think. I wouldn't put the snake up high on a perch, but if she's just climbing around the enclosure and slips, you will be fine.