The Angriest Danio.. Ideas?

[pitcairnpete]

Do not ask me why, but today when I woke up feeling a little peed off, it was nothing compared to one of my danio. Its a healthy female and all she is doing is boosting after every other danio left right and centre.

Any ideas?

 

[KittyKat]

Set up information?

 

[N0body Of The Goat]

Danios have a habit of getting spiteful with each other when kept in small numbers, a group of ~10+ in a 4-foot long tank with plenty of upper water current and a temp of ~20C will not only look great, but will be fish heaven to to lively little soles!