I think we all know how our Betta act in different situations. Some will get upset when you change the water in there tank, Some will hide for hours back in the plants when you put something new (decor) in their tank. I know my oldest betta Gunny has a routine and if it is broken he pouts. (but not for long) He never minded changes in his tank. He took those changes in stride, and explored them. However Ben my newest Boy really doesn't like changes to his plants. He didn't mind the new rocks, or the mystery snails when I added them.
But mess with his plants he goes bonkers. I replaced some of his bunch plants that were looking spindly yesterday. I replaced them with a tall Grass in the center of the tank in front of the filter to fill in a hole. That he just explored. I pulled the spindly bunch plants from the right side of his tank, and replaced them with a medium rosette sword, and a medium size amazon sword.
Now these plants will fill in, and spread in a few weeks, but according to Ben I have committed the most vial act of trespass. This is unforgivable to him. ( well for a few hours anyway). He swam in and through the new plants, came back out, and hovered in front of the tank glaring at me. Swam back into those new plants, came back to the front, and glared some more.
It was a very indigent stare. (as how dare you do this to my tank. up until about an hour ago he, wouldn't go near that side of the tank. finally about 20 min. ago I caught him back in the right side laying in the center of the rosette sward just as happy as he could be. He saw me looking and swam out to greet me like nothing ever happened. (I guess he's over his tantrum) However in all of this he never missed a meal. LOL
It's funny how these guys react, and let you know what sets them off. I wonder what he'll do when the new plants come in tomorrow for the new 55 gal., and I put some medium grasses in the front right side between the swords. I'll be ready for the scolding.