These are called pseudopupils. you can look down and see the dark pigment at the bottoms of the facets (ommatidia) that are pointed towards you. You can't see down to the bottom of facets that are angled away because there are shielding pigments present. It is like being able to see to the bottoms only of pipes that are pointing towards you. At night, the shielding pigments are withdrawn and it is like the pipes become transparent. You can now see the pigment at any angle. The insect is said to gain sensitivity to light at night but lose acuity of vision.

Thanx all for the help and comments!
Heimchen, that' cool. I would prefer if you could link to it here: http://www.photoportfolios.net/portfolio/pf.cgi?a=vp&pr=38446&b=up&st=1&la=81&ph=6&sid=18841&pi=APASTRON&u=18841
I am in the business of stock photography and worry about losing control of an image once it's diplayed on the net. The linked page is a little more difficult to copy pics from, and has all the appropriate contact information for licensing. Just for kicks, I'll provide the terms "Yam'rii" and "Huk" in the keywords!

And thanks again for giving permission and offering that link (and tagging the picture!). I just posted the link plus a brief explanatory blurb on two threads at theforce.net, the Official General Grievous Club one and another thread in their literary forums that was created to discuss the Grievous character as more recently perceived by a couple of the Star Wars franchise's official creators. The first thread's pretty silly and casual, more teen posters than anything else, but the second one's a little more serious--people that work in professional visual/artistic fields may well have a look at your shot via that one. Here are the links to those threads. Look for the last post by 'Biddybot', the nerd with the Obi-Wan icon, if you want to see how I introduced your picture. :)

http://boards.theforce.net/star_wars_community/b10012/19798534/p355

http://boards.theforce.net/literature/b10003/21238198/p77

PS: :D As I was typing this up, two people have already looked at your photo and commented back on it...and one of them sounds to be a genuine mantid fan! Heh, just goes to show... Glad you have a sense of humour about all this. I'm guessing that you're always happiest when the most people are looking at and enjoying your photos...even if some of them are now going to be Star Wars nuts!

Thanx for the kind words on those forums!
I have no idea what you guys are talking about over there, but it looks like fun!

...and didn't I just answer the guy who wanted the see a pink and white 'Huk', too! Thought he might like to know about why your subject's eyes were so unusually dark...

I actually had a bit of personal ulterior motive in asking you to allow linking this picture. You see, I'm something of a sci-fi fan, but in my case the interest is very much science-based, and I've always been a tad dismayed by how many people who likewise consider themselves sci-fi fans turn out to have very little interest in science at all. Anytime I see a good opportunity to draw attention to some real science while at the same time pursuing the fun fictional stuff, I jump at it, plus which I just like to see nice work of all kinds get the recognition it deserves. As for what the heck we're talking about over there, it's about all things revolving around a fairly new character that was introduced in the last Star Wars movie, General Grievous. He's unusual for me in that he's the first character from that universe that really gets both my inner science AND tech geek selves excited...he's both an alien and a heavy-duty cyborg. He's also turning out to be pretty popular, thus the continuing interest more than a year after his debut. Before that, the only Star Wars characters that got me going at all were--you guessed it--the giant space termite dudes, the insectoid Geonosians. I think I'm about the only person who's a big fan of them, though.

I added two more pics from the "session"...