Sexual attraction is all in your brain. At least if you're a nematode.
Ricardipus has a great image if you want to see a nematode picture.
I always thought worms were hermaphrodites (both male and female) but the story, as usual, turns out to be a bit more complex. Researchers at the University of Utah have found that worms have definite preferences for one sex or the other. And, if they kill off certain kinds of cells, the preference for one sex or another can change.
From the University ... Read more