Neon Nonsense!

Teishokue

schooling is a defensive technique, they usually dont school untill stressed by a predator/others. other than that they will expand the tank and "spar"

AbbeysDad

I don't think that's entirely accurate - yes, shoaling fish are better protected by their numbers when schooling, but it is as much a social arrangement for other factors as well such as mating, finding food...
The Neon Tetras in my tank will school at various times, especially it seems in the early evening hours and there are no threats against them in this tank.

I now think that the sparing is more like play fighting I think.
(When yer a little Neon Tetra, you gotta have attitude!)

Teishokue

the threat is YOU????

TwinDad

My Lemon Tetra's spar too. It's fun to watch.

Many times they are swimming around the tank in a small group with a few that wander off. But when I come by at various time to watch they call come out and form a group. They think it's feeding time.