In the time it took me to get the reCAPTCHA module installed on the registration page last night, there were 8 bots that registered users. It's now been about 12 hours, and there are no new successful registrations. I did check to make sure that it still works, and it does, so all is well.
I just needed to go to the CAPTCHA admin page, go to the "CAPTCHA points" tab, and enable the user_register_form, then edit it to do a reCAPTCHA. Well, I needed to register the site with google to get keys.