Neon Tetras suddenly chasing each other....

[Joe_D]

I have six Neon Tetras
For about a month, they have been peacefully schooling and then hiding among the plants at night to sleep They were all acting quite normal. .

However, this morning when I turned on the light they we chasing each other and sill are hours later...then some seem to be taking refuse among the plants..
What would cause this sudden chasing ?

Is this some sort of mating behavior?

EDIT....
It is now early evening and the Neons have seemed to settle down for the most part.. However, they are not more or less tightly schooling as before .

 

[Joe_D]

Now they are back to normal and peacefully schooling

Nothing changed..... before or after
Water parameters, including temp, are excellent and stable. .
It has me baffled.

 

[gilpi]

Trying to figure out fish behavior will make one crazy. Neon are schooling fish, for them to show their schooling manners you would need a lot more than six of them. The size of your tank will determine how many you should keep.

 

[Joe_D]

I discovered something interesting..
As it turned out, something did change.

I recently got a nice glass hood that replaced my cheap black plastic one that just had 6 white LEDs..
To go with it, I got a nice high tech light that is great for my plants.... with may white LEDs and a few red and blue ones..
The light has many different settings including a few brightness levels

Long story short..........
At first I had it on one of the brightest settings.
i eventually realized that maybe they do not like that bright setting
So, I bought the brightness down a bit and now they are now really peacefully schooling etc.. I discovered this just by experimenting. .

Even the Rasboras are more peaceful..

if their natural habitat is somewhat brackish water, that might explain it..​