My guess about the Drengins, seeing as FrogBoy has stated many times in the distant past (Brad: do you still feel this way?) about how he wanted them to look like frogs, is that they reproduce more like terrestrial frogs do, and their social makeup is also more like frogs, including being able to change gender as needed.
I could see that for the Torians (it's how I envision them already), but the Drengin!? 
You wouldn't happen to have a link to one of those statements by Frogboy, would you?
Anyhow, we already know a little about the life-cycle of the Yor. Two of their techs in TotA gave some small details:
"Advanced Population Acceleration
We don't breed.
As a cybernetic species, we do not experience birth or childhood. We are manufactured and when the time is right, the holy spark gives us consciousness.
Needless to say, there are very real limitations on how fast we can manufacture more of our kind. This is particularly problematic as the holy spark only exists in one place that no one may speak of. The result has been that our population growth has been very slow relative to other civilizations.
Advanced Population Accleration evens the odds. Using secret techniques we are able to distribute the holy spark across our worlds to bring to sentience our kind faster."
and
"Extended Lifetime
The spark of life fades from us over time. We do not understand the mechanism of it. Our species is cybernetic. That is, we are ultimately machines.
As machines, we have, in theory, an unlimited lifespan. But, for some reason, we die. We have only the slightest understanding of what causes this but ultimately, the spark of life begins to fade and eventually, even the most potent of our race loses its sentience and returns to being an animated machine much as we were when we were created by the Iconians.
However, through time we have learned how to slow down the fading of the spark of life. It is only a little bit but it allows us to significantly increase our net population growth on planets."
In other words, the Yor are more than simple robots. They actually have some kind of "soul" which gives them sentience.
