Hi,
There is no way you can prevent an uncaged pair, or even an uncaged female from laying eggs. Allowing birds to roam this way is very dangerous for them. There are so many things in a home that can harm them. They are very likely to fly out a door at some point. When you let them roam like this, it mimics searching for a nesting spot. Pet birds truly do best if they have a home base. A large cage with toys and enrichment is comforting to a pet bird. Pet birds should always be supervised when out of the cage. Letting them roam without supervision is the same as letting a small child wander around unattended. I’ll give you a list of things to change should you decide to get them an enclosure for their own safety.
Keep in mind that in the wild for breeding, she needs longer daylight, warmer weather, abundant food, and a quiet, private environment. The goal is to reverse these conditions.
Limit their light to 8-10 hours by covering the cage early each evening
Do not give them anything to use as a nest – no bird huts or tents, no box, bowl, etc. If she decides to sit in a food bowl, remove it and replace with smaller cups.
Do not give them anything to shred such as paper or cardboard.
Rearrange the toys in the cage frequently.
Move the cage to a different place in the room. Move the cage about once a week, or whenever they show signs of nesting – settling on the cage floor for example. This disrupts her idea of having a stable place to lay eggs and raise chicks.
If you feed a lot of fresh foods, stop offering any for a couple of weeks, and then only offer them in small amounts about 2 or 3 times a week. You can resume normal feeding later when the birds aren’t being hormonal.
When they are let out of the cage, do not let them get in any dark cozy places and don’t give them free roam. When you let them roam around, this mimics searching for a nesting site.
When you handle them, limit any petting to only the head and neck – do not pet a bird on the body. Only a bonded mate is allowed to groom the body. We can’t be a mate, so touching the body is off limits.
If there is no metal floor grate, then do not use any bedding or paper in the cage tray – leave it bare and clean it daily.
Thank you for asking Lafeber,
Brenda