Fortunately for Mike, the girls seem to enjoy keeping him in the birdcage as some kind of symbol of their triumph. That's totally fine from his perspective, as they only treat their captives worse as they go along. In fact, the very first evening after they gain control of the gun, one of the girls picks up her ex-boyfriend off the table and just drops him down her panties like he was nothing. "That's where he belongs," she says with a grin, and when that happens, the other girls all laugh. "New rule," says the sorority president. "Anytime you want to carry someone around, from now on, you have to carry him around in your panties."
The girls all laugh again, and sure enough, from then on, that's how they carry people around the sorority house. That goes for when they take their tiny captives back into their bedrooms, too. From Mike’s vantage point in the birdcage swinging around in the living room, he can see what the tiny victims are like when they're brought back to the table and pulled out of some sorority girl's panties after a long night alone with a giantess. They always look terrible.
It's especially humiliating for the girls: a few days ago they were bitter rivals with these sorority girls, always struggling for an advantage or a way to bring them down, and now they're being unceremoniously dropped down their now giant rivals' panties. The sorority girls really enjoy having their most hated enemies forced against their most private parts, as some sort of epic revenge for all their imagined slights.
Of course, it's pretty bad for the guys too. The guys who have been shrunken are often the ex-boyfriends of the sorority girls, guys who got sick of the nonsense and bullshit in their relationships. Now, though, they are completely at the mercy of their ex-girlfriends. Before those guys could simply refuse to have sex when their girlfriend was being annoying or they weren't in the mood, but now they are forced to cater to whatever whims their giant exes may have, both sexual and otherwise. And with all the bitterness that comes in ending a relationship, usually the giant ex-girlfriends have a lot of latent resentment towards these guys. They let them know.
So it's a bad situation from Mike’s perspective, even if the girls haven't taken him out of his cage yet to torture and use him personally. But he knows it's just a matter of time. There are some girls in the house who seem nicer than others, including at least one or two who seem visibly uncomfortable with the new regime of ruling over their tiny enemies. Maybe one of them will help liberate these tiny captives, or at least help him escape.
Of course, he worries that he'll draw attention to himself too. He’s avoided the torture and humiliation so far, and he’s not sure he wants to be subject to the whims of a sadistic sorority girl.