When does the ''intense'' music start?

[bozdogan080]

When you get raided, it usually starts playing intense music from the soundtrack. So, when does it start?

Does it start when they start to assault you?
Does it start when one of your colonists get attacked?
Or does it start when you get the raid message?

[Nameless]

Feels like it starts playing soon after they start moving to attack you sine that music doesn't play immediately if they decide to hang around for a while before attacking.

[fritzgryphon]

Not sure, but it doesn't seem to play if the raid is too small (relative to your colony size).

I had a raid of 1 enemy, and no music played.