Kept indoors under controlled conditions, they'll breed year-round.As with most birds, you're better off to hold that production to a few clutches per season, otherwise the Javas will just keep on going if you let them.Javas will often seek out the oats in a Parakeet mix and will sift through the seed until they find it all.In a gravity feeder, this means they will drain the entire supply and scatter the seed looking for the oats.It is best to offer them and they will eagerly take egg food (Roy's egg food mix), gamebird crumbles and green food.I have never seen them eat live food, but suppose they could be enticed to if you really insist (but why feed livefood if you don't have to).On a male in breeding condition, the culmen (the top of the beak, especially where it meets the head) has an apparent swelling.
There are a number of ways to distinguish between the sexes.
Hay, pine needles, coconut fiber and newspaper are their choices.
Some will make use of the coco fiber and weave an intricate nest.
Unlike most mannikins, you can actually hear it for some distance.
Waiting for them to sing can be a test of patience however.