Bats see in the dark but not invisible

[Albahan]

Bats are blind, they use sonar, they should be able to know the location of an invisible PC

I suppose this may not exactly be a 'bug' per-say but it just makes sense for a bat to know the location of an invisible PC especially since it can already see in the dark.

[adom-admin]

ADOM bats now can see invisible.