As you are attacking these, you'll get a message about the iaculus starts to bleed, and a pool of it's blood forming on the ground. The pool of blood conned yellow to me at 43, but it didn't do anything. I didn't get a chance to see if it was neutral or aggro, because I was trying to kill the red iaculus at the time.
A little bit later, the pool of blood transformed into a baby scorpion. We got anywhere from one to five scorps out of one iaculus. They also conned yellow, and they were neutral. Most of them took off running pretty fast, and we weren't sure where they ended up. One of them stuck around, and my friend decided to solo it. Near the end of the fight, it transformed again and became an adolescent scorpion.