I never breed my veiled females until they are a year old. I like to make sure they are done growing themselves before I put the demand of producing fertile eggs on them.
When I mate them, I take the female and hold her in front of the male's cage so they can see each other and watch for the reactions. If the female turns almost black in the background color, hisses, rocks back and forth, lunges at the male, etc. then she is non-receptive/gravid and you can put her back into her cage and try again in a few days.
If the male brightens his colors, coils and uncoils his tail, holds one hand up near his chin, inflates his gular pouch, etc. then he is not recognizing her as a receptive female. (He may also be reacting to the keeper.) If this is the way he is behaving, then don't put the female in his cage.
If he brightens his colors but does not show other signs of aggression then he is likely ready to accept her.
If she remains the "normal" green coloration (with the blue spots, etc. still there, of course) and moves slowly away from him, remains docile, etc. then she is willing to accept him.
If the two seem to be willing to get together, then you can put the female into the male's cage...but continue to watch them for a bit to ensure that things go well.
The female can stay in with the male until she shows rejection towards him and/or turns dark in the background color...then she should be removed from his cage.
If the female is already producing eggs, she may mate or she may show the male her dark colors/aggressive behavior. If she mates, then she may "dump" the infertile eggs she was working on and then go on to lay a fertile clutch earlier than the 30 days that it would normally take her to lay them.
If the diet/temps. are controlled, a female veiled won't likely lay any eggs until the keeper choses to mate her/alter her diet and temperatures. It also helps to make them lay smaller clutches...and live longer. I have had quite a few that have lived to be over 6 years old that have never laid a single egg. I also have had some that didn't lay an egg until they were over 3 and I chose to mate her. Her eggs were all good and everyone hatched. 95% if them were still alive 3 months later.
Hope this helps!
