If worms could talk, they might tell potential suitors, "I like the way you wriggle," complete with that telltale come slither look. But worms send their valentines via signals known as pheromones, a complex chemical code researchers are now cracking, according to a study published Wednesday (July 23) in the journal Nature.

Pheromones are like the molecules you taste as you chomp on a greasy french fry: big and fatty.