It appears that nothing happened

Peter let out a sigh of relief. "Thank god that was a dud," he muttered before shaking his head. "This is why you don't meddle with-" He turned only to see that Felicia was long gone. "And of course she disappeared." He scoffed and leapt to the vent he'd used to sneak in, not wanting to be around when Dr. O'Malley came in.

Of course had he stuck around he might have learned that the Doctor's notes made clear that the process was a slow one, as that better allowed for the body to adapt to the changes. In fact according to O'Malley's notes many times the subjects didn't even seem to realize they were being changed. The rats she'd turned into rabbits merely began to behave like rabbits, began to show traits of rabbits, and eventually were just rabbits.

Another thing Peter and Felicia would have learned is the process was sped up by, of all things, the chemicals released in the brain during sex...

As Peter swung on patrol he put the entire situation out of his mind. the device didn't work so there was no danger to it. And he really did hope Felicia was telling the truth when she said that she just wanted to help. He really didn't want to fight her again.

Pausing as he passed by the fish market he only stopped for a moment before he fired off a webline, snagging a fresh piece of tuna and leaving a 20 for the merchant. He suddenly had a craving for fish.

Meanwhile, Felicia had returned to her apartment, gone to open a bottle of wine... and put it away in favor of guzzling milk straight from the carton.