Large insect taking up residence

I first saw the huge green insect about four days ago. As I came up the steps leading into our house, I noticed a big splotch of green on the railing. Upon closer look, I could see that it's a praying mantis. It's long body is at least four inches long. Now that it has been there for several days, even through a hard wind storm, I'm curious as to why it chose to latch onto the rough wood there and not in the grass or on the rose bushes.

It's my understanding that the female praying mantis bites off the head of its mate during mating, so I've wondered if this bug is just resting from such a session, or if she's laid eggs there, since they stay with them, I have read. I can't see any, but then I don't want to get too close because I don't want it to jump up in my face. That would freak me out. Whether it is a male or female I don't know. I hear they are solitary creatures (especially when the females get rid of the males the way they do). 

  The cat, who also shares the front stoop when she goes outside on a leash, apparently has not seen the praying mantis yet, and the insect (are they really insects?) must not consider her much of a threat because it's still there. I did probably give it a scare the other night while letting the cat in. As I opened the door, my other hand reached over to the rail, and I felt something odd, and suddenly realized I had placed it atop the mantis, which kind of gave me the "willies." But when I looked, it had just moved a couple of inches over the side, but clung stubbornly to its place on the rail.  It was still there when I left for work this morning.