Fighting Tetras?

[Fraoch]

ive had 5 neon tetras for about 2 months and now they have grown to adult size, over the last month they have been fighting/chasing each other almost non stop. they're seems to be 2 bigger ones that chase the others more, but they all have their moments. is this normal or are they just being bad tempered?

 

[hedgehog738]

Have a look at their fins, see if they have been nipped. If not i think they should be fine

 

[Fraoch]

Have a look at their fins, see if they have been nipped. If not i think they should be fine

doesnt look like any damage has been done
is this territorial or are they just playing a bit of tig?