I know how you feel, some people say they are basically a automaton instinct machine, but I feel this may not be the case, keeping reptiles for most of my life, including boa constrictors which seem to have the most personality of any snake I've ever worked with....Maybe only rivaled by rattlesnakes...But point is, best policy if it seems the snake is poised and ready to bite it may just be best to leave them be, unless it's absolutely necessary to disturb them. Keep in mind now, aquariums are the worst possible thing to keep snakes in as it's hard to regulate humidity and just doesn't offer the security they need to feel. You can typically tell because they will coil up in the signature S position and will most likely hiss at you. If this is the case, just simply back off, check the humidity and temperature and put something around the enclosure to give them some privacy to cool off.
