There's a curious and slightly creepy effect when you look into the eyes of a mantis (or other creature with the same kind of eyes, like certain species of shri

There's a curious and slightly creepy effect when you look into the eyes of a mantis (or other creature with the same kind of eyes, like certain species of shrimp), and dark "pupils" seem to be staring directly at you. Those aren't real pupils, however, but pseudopupils -- an optical effect where you happen to be looking at a straight line into one of the facets that make up the compound eyes. Seen head on, the ommatidia appear dark or black, while the surrounding ommatidia reflect the light outwards.