Tropical Fish Forums

[Shai]

Some bettas will attack their tail (especially if it's a very large tail) because they mistake it for another betta creeping up behind them, ready to attack.

Personally, I suspect part of this tendency must come from feeling insecure. If your betta isn't comfortable in his environment he's more likely to be nervous and on the defensive, even if there's nothing to spook at.
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[Learn To Fly]

Yeah he was in my community tank, however now he is in his own tank and it's growing back. It probably was an insecurity issue then, though he -looked- pretty comfortable.
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[nikelodeon79]

Yup, tail eating definitely happens. Is he within sight of the other male betta? If so, he could be frustrated that he can't get to him to beat the tar out of him.

As to your original question, keep in mind that bettas are very determined, very slippery fish. They seem to have an uncanny ability to escape their confines if another male betta is nearby... and it usually doesn't end well.

If you take filter media out of your established tank and put it into your new tank, you'll have an instant cycle and there is no need to wait to put your fish in.
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