My betta is making a bubble nest?

[Kiwimommy]

I'm so confused!
I have two male bettas in two separate tanks..
One is very active. He swims a ton, eats his food within minutes and is just all around very healthy.
The other is more of a slow swimmer, often leaves some food after eating and seems pretty laid back.
The slower, less active fish made a bubble nest a couple days ago and I'm not sure why. There's no way he can see the other fish, so I'm absolutely puzzled. I've never seen any other bettas I've owned making bubble nests.
Any idea why?

[JKfish]

:) Bettas make bubblenests, it's just sort of an instinct for them. Mainly you'll see them making bubblenests when they are happy (physically and mentally healthy), though that's not always the case. I know one of my boys was making a bubblenest in his cold and dirty cup in Petsmart when I bought him.

[Kiwimommy]

Oh alright! Glad to hear it then. I was beginning to think he was a crazy fish!
I wonder if my other boy will make a bubblenest.. Hmm..

[newarkhiphop]

http://www.bettafish.com/showthread.php?t=69694