More females than males 3:1 if keeping them as a commune.
Too little females and the males will become very aggressive toward one another.
otherwise just keep a sexed trio 1 male : 2 females.
Regards
C
looks like i,ve got 1 to 1 ,hard to tell at the mo they are so small 1/2 inch thats all, but the one does not have much colour in its tail,might go back and get another female
