Antsy Tomcat

My cats have been driving me insane lately. I normally feed them just before going to bed, so that they don't wake me up earlier than I want to get up. In the last week, however, this tactic has no longer been working.

Before I can even get to sleep, the tomcat goes after the female, chasing her, cornering her, and generally just hassling her. She typically responds by growling/hissing at him, swiping him with her paws, or just running away. Running away just eggs him on more, and he often ends up chasing her around the house, with both of them knocking things over as they go.

Naturally, this keeps me from falling asleep in the first place. Yelling at them has no effect, nor does chasing the tom from the female. No sooner than I return to bed than he starts in again.

This is fairly new behavior for him. Normally, once he's eaten, he's ready to lay down and sack out for the night. If he were human, I chalk up his antsiness to being horny. At least that's how I act when it's been too long since I've gotten laid. But he's fixed, so I can't really attribute his behavior to simply being horny. As far as I know, neutered animals don't retain their libidos, though I could be wrong.

I hope this is just a phase he's going through and I don't have to go through this crap every night before I can go to sleep.