Speaking of that.
Does killing Black Beetle's beetle count as murder? They seem sentient.
Printable View
No; it counts as war, or at the very least, self-defence. Black Beetle is an enemy combatant, who was attempting to kill Blue's scarab; it was proportionate retaliation. Black was just less resistant to the same attack method, as he was 'on mode' instead of symbiotic with his scarab like Jamie is (which likely made Blue's retailiation more powerful, too).
(Also, it's entirely possible that Black's scarab wasn't sapient (which is the word you're looking for, not sentient) due to having, presumably, never been 'crashed'.)
Even the crashed Blue Scarab, early on, doesn't display much in the way of sentience. It doesn't do anything that a tactical database with a voice command couldn't - "Situation X occurs, suggest solution Y."
It doesn't adapt "Solution Y" to the fact that Jamie clearly and obviously prefers some solutions to others, or make allowances for a certain style of combat, or learn not to suggest things that its symbiote dislikes, or anything that would indicate learning or emotions. It barely displays life, let alone sentience.
It doesn't display any real kind of learning until after it is dominated by the Reach itself, when it acknowledges that it might have been comfortable with Hymie after all. I honestly think of it as being closer to a pet than a sentient being.