Apparently, their brains are just a little ring of cells that release amino acids and maybe have something to do with metabolism. The nervous system actually controls most things.
I don't know how they know to do this. Not even just instinct. But if a shrimp dies and eggs were already fertilized, they finish developing. I have seen babies coming up from the graveyard.
@weirdfizz I said a few days ago that I had one remaining shrimp in my tank.
Well, now there are 3. One big one, and two that got big enough for me to notice them.
@NoahPaulLeGies The babies are so tiny! Easy to miss until you've suddenly got more shrimp.
@NoahPaulLeGies That's great! I'd bet you had some eggs sitting at the bottom that finally hatched.