do i keep another bird in the cage with 2 others that are go

  i have 3 budgies and 2 of them are going to breed should i keep the third 1 in the cage or put in another cage?

thx
Have you already seen them mate? If so, put the third bird in a separate cage right up against theirs. That way they are not completely cut out of the flock. Also, hearing other birds encourages them to mate. Do you have a nesting box? Do you have 2 females or 2 males? 2 males could fight over the female, so he would have to to be removed immediately. 2 females could fight or you could end up with 2 clutches, so it is your choice how much time, money and space to have to spend on these guys. I sure do hope you did all your research before deciding to breed. I researched for 4 years before breeding my girl. Good luck with your babies!