Aliens: Dark Descent Bug Queen takes no damage until alerted

1. Select a mission with a queen 2. Ensure you have 1 recon with silenced sniper 3. Find queen 4. Find a position to fire recon sniper at queen without alerting queen 5. Observe Headshot on queen 6. Repeat several times 7. Observe Queen does not die 8. Alert queen 9. Observe health is still at 100% Don't know if this is just to stop a 4/5 man recon cheese wiping queen