Mantis watch

We have a bronze fennel plant next to the back door. So far this year it's between 3 and 4 feet tall, with feathery new growth starting as a darker bronze shade that turns greener with age. The top bits of foliage have scattered light green dots that might be aphids. Also hanging out in the upper foliage are young mantises. As of Monday there were six of them visible, all brownish, perhaps up to an inch long, with flat backs. This morning I see two. Already they are larger, greener, and now intermittently adopting the characteristic mantis posture: thorax raised, front legs lifted and folded. Their brown and green shading blends into the fennel nicely. I'm not worried about the aphids (if that's what they are) but I do wonder about the whereabouts of those other mantis siblings.