That is true as most keepers observe the same thing most of the time. Feeding, presence of a threat; could be other tankmates, dim lighting, being handled out of the water etc.
If anyone have kept Datnoid long enough, one would care less about the Dat being stable.
I mean.. a true Dat keeper would have understood this long ago that having a Dat swimming and interacting with its surrounding is far more rewarding than having one that tow itself away in a corner of the tank MOST of the time.
Then again, to have a "stable" one is just an awesome sight to enjoy.