How far apart do those 2 little bumps need to be below the vent to indicate egg laying is coming soon? I am getting so impatient with my freeloading girls. Their combs and waddles are very red, they are of right age, but they are holding out on me I think just to drive me nuts. I am also having problems with my younger girls sleeping in the nest box so I have then blocked. I want to open them for the big girls in case the time is getting close