A bubblenest is not the only indication of happiness, nor does making one always mean he is happy. I have seen Bettas in horrible tiny cups making bubblenests and I seriously doubt they were happy! Sometimes they do it because they are stressed. Maybe it helps calm them? Some will make one and some never do. If the tank is filtered he may have tried making a few bubbles but they won't stick together because of the filter. Don't worry about it either way.
Thanks for responding!
I thought the filter may have something to do with it, though one side of the tank is pretty calm.
He seems good in all other areas. His fin rot is clearing up too (i think, it's kind of hard to tell.) I finnally have his tank the way I want it! Now I just need to get another tank so I can have another betta!
I have 4 male bettas and only one of the present ones has made a bubblenest and I refuse to believe that the rest of them are unhappy so I do not worry about it one bit. I do believe that it is a sign of happiness but also a natural part of their development in some cases.
I have heard of Bettas who never built a bubblenest in their life. Most will sometime, but if they don't it doesn't mean they aren't happy.(as others said) Fuego here has built giant bubblenests while Dorado has never blown a bubble...and considering Dorado has four times more space to swim around in, I don't think it's because he is unhappy.
Our Betta used to build bubblenests when he was in a fish bowl, but now that he's in a filtered, aerated tank he doesn't do it. I've read that, if they build one that gets destroyed, they get a little bent-out-of-shape about it. It could be that ours has given up producing one because they won't hold together in all of the currents, or maybe he thinks that the collection of bubbles arising from the aeration is his own bubblenest (he does tend to examine the integrity of the aeration-related collection of bubbles as he used to examine the nests he would blow). He doesn't seem unhappy, though.