why are my budgies throwing out their eggs?

Question
Hi, I have two breeding pairs of budgies in an aviary, one of the pairs is laying eggs quite frequently in her nesting box.
Twice I have found the eggs have been thrown out of the cage onto the aviary floor, the first time it was just eggs unhatched but fertilized, the second time two eggs and a hatched chick had been removed, ..
I have no idea how to stop this from happening.. and I dont know why they are doing it, or who is doing it... the male or female, do you have any advice as to how I can stop them from throwing out their eggs?
thankyou  
Jolene

Answer
Hello Jolene! If you have two breeding pairs (2 males and 2 females) Then The other breeding female is probably the one throwing out the eggs and chicks. Breeding hens are very aggressive twords other females and will go into the other hens nest and kill the babies and eggs. They do this because in the wild the smarter hen wins the nest site. Even if that means killing the other hens chicks. That even happened to me to,i housed 2 hens in the same cage thinking the male would protect them. 3 babies were born and when the oldest was 10 days i came home to find the other hen with blood all over her face from killing the chicks. You must seperate the 2 pairs into different cages as soon as possible. This should totally eliminate the problem. good luck!