Earlier this month, I noted the fact that Max and Beeps don't like each other and that they use the stand to attack each other.
Yesterday, Beeps saw newly placed paper, so of course he had to go play in it and try to empty the paper from the tray to the floor (he was ultimately successful with this goal). Since he was below the grate, Max went over to try to instigate a fight with him. Beeps wanted nothing to do with her!
It was pretty funny. Max was getting frustrated because she was antagonizing Beeps, and he was happy playing, completely ignoring her threats. She would follow him around on top of the grate, trying to get him to fight her.
Beeps did finally give in and fight her, but only after he'd emptied the tray and Max had been bothering him for over 20 minutes.