i have cutted the circle of wires of my cage to attach the nest box out of the cage and now i'm worried how to block or close that hole....how do u close the hole when u cut your cages wires to attach the nest box

A breeding cage should be used for breeding only. When they are not breeding they should be housed in another cage or aviary... therefor you don't need to cover the hole because you wont be using the cage.

You can keep the nestbox attached if you want and just block the hole so that they can't use it when not breeding... How big is the cage that has the wire fronts?

Use a spare piece of wire mesh or attach a piece of wood over the hole when not in use.

I just use a piece of wire or wood like Kaz says when I don't want birds breeding.

thank u all of u guys