We extracted the Praying Mantis oothecae while clearcutting the decorative grasses bracketing the front door. As far as I can tell, they’re still charged up and ready for use.
The masses resemble rigid foam wrapped around grass stems:
It’s a mechanical joint, not an adhesive bond, and the dried stems slide freely through the openings:
From one side:
And the other:
They’re now tied to stems of the bushes along the front of the house, which (I hope) will resemble what the little ones expect to find when they emerge, whenever they do.
The Smell of Molten Projects in the Morning 
Always a neat find, but just be aware that this is from a Chinese mantid and not the native Carolina mantid. As someone once said, “they eat bumble bees like popcorn”. Even though the mantids themselves are easily predated when they are first emerging, they are also often taken out by birds since they are rather slow and clumsy pilots. While I don’t actively seek and destroy them, I no longer save and relocate every one I find, and let nature take its course. I have actually never found a native Carolina mantid or egg mass on my property (10 acres) but do know they exist in the area. It’s amazing what will show up when the right conditions exist for it. My wife’s passion was native plants. By specifically planting certain ones to attract native pollinators that we had never seen before, they had shown up within a few years.
By now, I think they’ve been here long enough to pass as locals.
I expected something to treat those egg masses like lollypops, but they’re still on the bush!