I have three female rats. I've had them since Saturday. I haven't noticed any chewing on their hammocks or things in their cage, but when I have them out for free range time, they chew on my hoodie, my shirt, blankets that are on the couch, the couch cover, the bath mat if we're in the bathroom, they climb up on my shoulders to chew on the towels... But so far they haven't touched anything to chew in their cage. What's going on? I feel like they've decided to only chew on things that smell like me or something.