I would highly doubt they came in with ducks, herons or any other bird. The odds of that happening are about as low and you and I both winning a multimillion dollar lottery on the same day! We've debated the bird moving fish egg theory thoroughly on this forum. Highly unlikely! And, you are catching more than 1 of them... That means two eggs survived the trip on a bird's body, of different sexes and then pulled off a spawn all in that time period? I am better the bullheads swam up your drainage pipe. Bullheads and GSF love to swim up drainage pipes to make new homes. That or you got a contaminated order...
