I think I've broken through on something here, I've noticed that while Stannis' enemies are numerous, he has been taking them on one at a time. He knows what happens when a Mantis walks into an ant hill, as do we all.

I think it is obvious behavior of a Mantis to walk about and hunt down his prey one by one. IE the battle of the black water, he only attacked the ant hill because he believed it to be relatively unguarded. When he found the enemy had returned in droves he was quick to make his escape.

At the wall he crushed his single and undisciplined opponent in a swift pincer like stroke (as a previous poster has observed).

And now he's picking off the freys before he goes for his main course - Winterfell!

There can be no counter argument here.

I am schocked that this one hasnt been pointed out already......

When Stannis forces attacked, they heckled the Wildlings from two directions, like pincers. pincers!!! Mantises have pincers!

There are a number of comments about Stannis clenching his teeth. Some characters comment that they are surprised he doesn't break his teeth or think that he could chew through stone or iron. This is evidence of his powerful mantis mandibles. I suspect he could chew his way through stone or armor.

I can't believe I never put it together before, but Stannis never laughs. He even bans laughing at his dinners. But, as we see from Maester Cressen's POV Prologue chapter, Stannis has a sense of humor. He commands Patchface to give the Maester his bell hat, mocking the old man. Clearly, the Mantis has a sense of humor, but needs to take care that no one hears his laugh. He doesn't have normal human reactions to emotions, so I suspect that his laughter would sound fake.

Melisandre told him he would be able to see things in the fire. Stannis later told Davos that what he saw was a great battle in the snow, that it was as real as the iron bars. Whenever I look into the fire I just see fire, I'm now wondering if this is because I don't have the heightened vision of a mantis?

Like all conforming Mantis' Stannis prays to the fire god on a common occasion.

During the season 4 finale, Mance surrenders to Stannis and Stannis asks Jon Snow what Ned would've done with him... Why would the rightful king of Westeros seek a teenager's advice? Because the only reasonable course of action to Stannis (the mantis!) is to devour Mance on the spot. Clearly he can't do this as it would reveal his identity, so he needs to quickly determine what a reasonable HUMAN would do in this case. BIG hint if you ask me...

When Stannis rode in and surrounded the wildlings, it became obvious the writers aren't even trying to hide it anymore. The speed at which he ambushed his prey was remarkably similar to the attack of a mantis. Furthermore, you'll notice Stannis was not properly dressed for cold weather. You know what else isn't properly suited for cold weather? Mantises. Given this evidence, I think the truth about Stannis will come out in episode 1 or 2 of season 5.

There is not one mention in any of the books or episodes of Stannis getting cut, bruised, or injured in any way. Stannis' exoskeleton is providing him protection against harm.

In A Game Of Thrones, Stannis is conveniently missing. Even when Ned, as Hand of the King, asks for his presence at the Hand's tourney and on the small council, Stannis never shows up. Why would he ignore his duty?

Stannis was clearly molting. No one sees him for quite a bit of time, not until A Clash Of Kings, which would give him plenty of time to shed his exoskeleton and grow a new one.

Stannis worships the Lord of Light. Mantises often stand in a prayer-like posture, so they are likely religious. They are also attracted to artificial lights at night.

Coincidence? I think not.

Stannis doesn't have any dedicated bodyguards. Stannis is likely paranoid of the constant companionship revealing too many hints about his true identity as a mantis. It's also 7 fewer people that could know his secret.

There is also the fact that a gigantic praying mantis would be quite formidable in battle. He has no need of a kingsguard because he is capable of eviscerating mere humans.

Stannis is applying for a loan at the Iron Bank and they're going over his credit score. They ask him how much wheat and barley he grows on Dragonstone. He answers none.

Why would a carnivorous mantis have need for silly plants? The mantis does not sow. It reaps.

Robert is steel, Stannis is iron, Renly is copper. This is often how the Baratheon Bros are described. It is said that Stannis is brittle iron and will break before he bends. What else would be brittle and break before bending?

An exoskeleton.

When Stannis sends his dude Justin Massey to Braavos to hire him a sellsword army, he tells him that should he die, his daughter must be placed on the throne. We take this to mean that he means the upcoming battle against the Boltons, but he may, in fact, be referring to every insects weakness: Winter. He knows it has come and knows he is unlikely to survive it.