My male corn definitely knows there's a female nearby. Not only did his behaviour change when I got her (he calmed down and got alot more tractable), if I handle him right after I've handled her, he'll sit there and smell me for several minutes. It's really neat to watch.
(another interesting unrelated thing - if one of us has a corn, and someone else in the room has say, a python, the corn will freeze if they get close enough.)