I have them in my yard as well. People who are big on vegetable or fruit gardens will actually buy those eggs and hatch them in their garden to protect their crops from mites and bugs.
I played 16 inch softball 5 or 6 nights a week all over the city and suburbs. The Mantises would be out and about feeding on mosquitoes, a lot of times up near the light posts, but also all across outfield grasses.
That being said, I'm definitely not certain it's a mantis, I only hope it is
Nature and shit.