I have 3 GloFish tetras and 3 GloFish danios. My tetras consist of two males and one female (not intentional). But how the mating ritual starts from what I've seen and researched, the males begin changing the female aggressively trying to get as close as possible to her.
I pay close attention to my fish behaviors, if your the same. You'll notice this behavior as odd. So what I've done is bought a breeder box, one of those really fine screen boxes that hang off the side of the tank, to put the female and the older male in there to do their business. If you watch closely you'll see them flip over and the female releasing the eggs, they do that several times. When they stop chasing each other and stop I remove them carefully from the box and put them back in the tank.
You should be able to see the eggs, they look like small white pieces of sand. After several days they should hatch, I just had a batch hatch yesterday. And now I'm in the process of raising the fry. This will be my first time trying to raise the fry, wish me luck. I want to see what color they'll turn out, the female is green and the male is pink. From what I understand, it's not illegal to breed them, it's illegal to sell them.