Need Help With Dragon Movement - Controlling Flight

[Gruffydd]

I'm working on my first mod, which is a large underground "dungeon" environment (based on the classic D&D module In Search of the Unknown).

I'm adding something I'm calling "firelizards". They are very small dragons, not very tough, with the primary attack being the fire breath weapon (the stream, not the fireball).

I created a new race for them, then created the new skin, then created the new npc, and they look great and place in the cave where I want them just fine.

However, I'm having a hell of a time controlling their movement.

 

I want them to either only fly in a VERY limited area, or to not go anywhere at all, just hovering and flapping their wings.

 

So far I have had no luck getting this to happen.

 

When I set them to Immobile, they hang in mid-air with no wing motion and a very twitchy rotation.

When I set them able to fly, they always immediately fly off into the big cave next door, where they fly around for a bit and then take off through a wall (because there is no collision detection for flying things, apparently).

 

I've searched various tutorial videos, forums, etc., and have not been able to find anything that addresses this issue.

 

Would anyone be willing to tell me exactly what settings I need to set to either drastically limit their flight range (so I can keep them in the cave where they start) or just make them hover and flap their wings?