i got one guinea pig from Petsmart at the age of 3 months old, her name is ginny and she is about to turn one. After about one month, my friend was giving away 2 guinea pigs, they were like 3 years old so i got them and i got them a really big cage and they never fought till now. i got them a top level to their house and my little piggy(ginny) was there and so was one of my big pigs (CoCo) and coco was being really mean and pushed her off the top level and she fell down the ramp and i got so scared that maybe she got hurt but thank god she didn't. I dont know what to do because its almost happened before do i sell the mean one or do i separate them?