They lived together for almost a year and they were born sisters from the same mom. I had to observe if they continued to fight when put together thus filming them. I put up for the sake of answers to the problem and categorized the video under "Pets & Animals" instead of "Entertainment". THIS VIDEO IS NOT FOR ENTERTAINMENT. If some of you choose to treat it as such, then that's your problem, psychologically.
Apparently after 6 - 7 months of living with each other, one of them lost its scent of the other one. That, in turn, caused it to mistake the other for its enemy. "sighs" they are considered twin sisters. Right now, they are in separate cages, cages which are big enough for 2 hamsters. The white one, Teddy, is the one who lost the scent of the grey one, Rex, and even bit Rex till she bled which dried up pretty fast. Just for the record, Rex is the more hyper hamster and Teddy is the less-playful hamster. Instead, things turned around. So weird, just so weird.
ps. Btw, they fought more than this short lil' video. I had to stop recording in order not to let Teddy inflict any more injuries to Rex.
