rebalance bats

[sem-geologist]

Hello,
This mod is really nice.
My game however suffers from bats.
AFAIK bats do not like bright light IRL. With current Animalia bat implementation It is impossible to keep my very well light dungeons clear from bats (I know there is the option to turn off guano production as that is the most annoying aspect from that, but logically bats should not spawn in well lit places (i.e. underground lab) at all), as they spawn inside my sealed spaces under 0 height. One of building has its floor at 0 with well light space, and bats spawns there. It looks currently bats can spawn even in the sunlight (light 15), as there is only min_light defined to 0, and no max_light (which in creatura lib defaults to 15).

So i suggest to add max_light = 7 for bat spawning (maybe some other value, but clearly bats should not spawn in well lit spaces, or settle and make a mess just few blocks above any light source). With fixing that issue the max_height=1 limit could be lifted. Bats normally should spawn in any dark cave (those in mountain side too, if it is dark enough).