I have no clue. I've never bred my birds and they've never mated on their own. They LOVE each other (as you can see in my sig) but they haven't mated once, which is good for me! I have no experience with raising chicks (because I would want them to be hand-fed if they ever get chicks). If they ever do decide to get chicks some day, I have no objections and I think it would be fun watching little baby tiels grow from an egg to a pretty bird. I just know that when breeding, the female needs LOTS of calcium, and she needs to have a comfortable nest to lay eggs. If the birds don't want to mate, I don't think you could make them. They do it when they want to hey! LOL Maybe your keets are not a bonded enough couple. I don't know, but my friends tiels decided to breed themselves for the first time one day when they were 6 years old. They never did it before that, but they got 6 healthy chicks that year and they were all beautiful! My friend handfed them! Then the next year they got 6 more! The next year 5 more! Then after that, a clutch of 7! Now they are 10 years old and so far have had 24 kids! My friend kept some, gave most to her cousins and friends. They all have loving homes and are very sweet tiels! Remember, you have to have LOTS of knowledge and responsibility when breeding your birds. You need to know signs of problems, when everything is fine, when the hen "may" need vet assistance (which may not be needed at all but sometimes is). Ps. Has your female keet ever laid eggs (even infertile ones)? If she hasn't, she probably isn't hormonal yet. My tiel has never laid eggs yet, but I KNOW Muffin is female because she's a pearl tiel and male pearls lose all their pearls after their first or second molt. Muffin has a back and wings FULL of pearls and she's 3 1/2 years old. She is also relatively quiet as female tiels are. Doesn't sing or whistle but has a very sweet "squack" and teeeeeeeeeee. She's as female as they can get! She's also a bit smaller than Popcorn as females are smaller than males.