Both the male and/or female will void their bladders/bowels. It's gonna be a mess. Have some fresh newspaper ready to go.
What I have been doing in putting the male in the female's tub. Once they make their mess I switch them to the male's tub for the actual lock while I clean the female's.
The female will cruise around the tub with her tail in the air and kind of jerking around if she is interested. Her vent will be open, she is laying scent tracks. The male may not seem interested at first, but just leave them together. This is my first year breeding but this is what I have witnessed so far.
After they have been paired a few days (witnessing a lock) I put the female back in her now clean tub.![]()