The finches you've got to watch. With the first batch of eggs my brother's finches laid, the male destroyed them all. Second time they mated, after the eggs were laid, he separated the male and female, and this time got a batch of baby finches.
Not sure what's going on, but the males can sometimes have quite an attitude problem.
I'll have to ask my mother if Tammy ever had eggs...
But I could see Jim doing that. I believe he was pecking actual feathers off her. We didn't know what to do about it. You can't shake your finger and yell "no!" .. tapping the cage just scares them both.