Hello and welcome to pettalk! First of all I would like to congratulate you on your babies! The same thing happened with my friends gerbil, they were supposed to both be males..but then one day one had babies so then they knew "he" was actually a she, and that is how I got my gerbil, she was 1 of the 3 pups. I have the same problem with my gerbil, I give her things to chew but she always chews on her wheel, but to help them from stop chewing their weel you can try those soft wood blocks that are flavored or you can try dog treats (yes it is ok to give them those) they really like the chicken flavor..it keeps thier teeth nice and trim. One way you could try to stop them from kicking their bedding out of the cage is to try to put less bedding or you could put plastic (the plastic wrap stuff) around the bottom so it cant get out. I hope this helps! Good luck!