I've heard all about "chinnie teenage rebellion" so I am wondering if perhaps that is what's going on here. The twins turn one on June 26th, 2010 and Arwen has developed a serious behavior issue. She's always been more standoffish than Esper, who is my lovebug, but now she is a total biotch! I give them playtime daily and Esper & Scully get very excited...whereas Arwen wants me to STAY AWAY! She barks at me, sprays me, bites me...I don't know what has become of her! Lately I've been coaxing her out for playtime by using the dustbath house...I wait for her to climb in and then I put her in the playpen by transporting her IN the dustbath house. Once she is having playtime she's really enjoying herself...but then once I'm back to take her to the cage she gets upset and throws a hissy fit. I know I should probably leave her be but I'm worried she will become even more anti-social if I don't at least include her with the other chins for playtime. Is it possible that maybe she is "in heat" and she's just going through some sort of chinchilla PMS? This behavior change is very recent...she never, ever bit me prior to three days ago. Help?!