These are the norns that never diiiie

So the wolfpotato run has just reached generation 20, and the population growth shows no signs of slowing down. I can not for the life of me get it down to a reasonable number-- it always stays up around 100. I need it to be at least half that.

I have put an egg collector in the bottom of the workshop so every newborn must find its way to the meso to have any chance of survival. I have put bacteria and poisonous plants in the hub. I have kill hots'd the vendors in the meso and replaced them with regrowing plants to limit the food supply. They are still breeding like crazy.

The population appearance isn't homogenized yet, but it's getting there. For the most part the norns have a zebra head and a chichi body, with the arms, legs, and tail being pretty evenly split between zebra and chichi. There are a couple still out there with a bondi body and a few with chichi heads.

I haven't seen a whole lot of color mutations, but I managed to catch pictures of these two pretty things:

I really do need to figure out how to curb the population growth. I'm not sure if my group has really become that resilient or if there are just so many norns so tightly packed together that they just end up breeding more than they die. In past experiments I have learned that, from birth, the average norn can live about 30 minutes without food before it starves. Considering a norn only needs to survive 45 minutes before it starts breeding, as long as a norn manages to grab a bit sometime within the first half-hour of it's life, it'll live long enough to pass on it's genetics. That really doesn't seem to be a very high requirement for a spot in the next generation's gene pool.

I use an agent called WolfMate that automatically exports norns once they reach old age. This is useful for many things-- for one, it gives me a genetic record of norns that had strong enough genetics to live out a full life in the run. If at some point the run completely dies out, I can import the last several creatures that have proven themselves, clone them as babies, and start up the run again. But looking at the exported creatures can also help me understand more about how my run is progressing.
For example... looking at my exported creatures folder, only four norns from the past 3 generations have actually survived to old age. Using this information I can guess the answer to my question above-- it seems my creatures are not extremely resilient; they are just so crowded that they manage to get in a couple of kisspops before they keel over.

With this in mind... I need to be careful when adding more hazards to this world in an attempt to curb the population growth, because I'm guessing there's a threshold; once I reach the point where the creatures are no longer so crowded that they are guaranteed to have a mate, the population could drop off very quickly.