Why does my bunny growl and lunge at me?

I have 2 bunnies, I dont know there age, but we are assuming around 4 months old. The people at the store we got them from did not know their age. But they were really nice and sweet when we had them inside, and we pet them and play with them, and let them outside to play for a while. But when we put them in their cage, and we didnt really let them out at all, one became very aggressive. She growls when I try and pet her and then she lunges at me, scratches and bites me too. And when I try and touch my male rabbit who is very tame, she lunges at me, but he doesnt do anything. I was thinking that it might be because she is stressed out being inside the cage all day because its only a 4x4. But I've become afraid of her, and I'm too scared to lift her out of the cage to let her play, so I have to try and shove her in a box to let her play. But Max(male bunny) is really sweet and tame. I dont understand. There has been some other weird behaviors too. Ruby(agressive female bunny) will chew up the card board box we put in there to let them nest in, and she just chews it all up and spreads it on the floor of the cage. I have put in 7 boxes, and she just chews them up, and spreads it around. I just dont want her being mean, and I dont know what to do. There is a possiblilty she is pregnant too. She lives with a male rabbit. Please help me.