I have two breeder tubs and then a male and female grow out tubs. Well i had about 10 or so females in their grow out tub and a while back I noticed a certain female looked an heck of a lot like a male from the back end well I cleaned all of the cages out this weekend and in the female cage I have a very large pile of babies and it looks to be another 2 or so prego females.
So a word from the unwise here check and recheck your males and females.