Bug or feature? (disappearing biters)

[Sir Nick]

So, I blast a biter base to bits and then it happens - a dozen or so biters chasing after me simply disappear into thin air. However, I believe I might have inadvertedly switched on peaceful mode while creating the map. Is this regular behaviour, or should I go on composing a bug report?

[ficolas]

In peaceful biters still spawn, but they only attack you when they see you.
I dont think this is intentional.

[Rens2Sea]

I'm experiencing the same thing when in peaceful mode.
It looks like if you destroy all spawners in a base the remaining biters will flee towards a nearby biters base, but if there are none nearby they just disappear.

[slpwnd]

It is both a bug and a feature

The feature is that when the biter "leaves" the spawner it has only a limited lifetime (something like 20 minutes). This is sort of a safety precaution to avoid some nasty situations that could lead to flooding the world with the biters.

The bug is that when the spawner is destroyed its biters don't have this counter set so they disappear (they should die) very soon.

This will be fixed in 0.9.