I would avoid letting mine go around my mouth and nose, for fear my exhaled breath might trigger something. lol
Apart from that, they're fine.
You will learn to read their body language over time. A snake that is considering striking gets a particularly tense look--they actually clench their jaw muscles.
Sit down and free hand pop for sex determination 100 baby burmese and see if ya don't get bitten a few times....You'll be a bloody mess when your done and be none the worse for wear..