They have sexes and lay eggs. If you want babies, feed them snails, and give them a calcium supplement. Those fish vacation feeder blocks work pretty well, or even calcium pills from the drug store. Possibly they can need iodine, but that is one I am not certain about.
Chopped beef heart is said to be taken if snails are not available as food. The eggs are rarely laid on glass, mainly on strong stems, like anubias. Not sure how long they take to hatch.