I have a Japanese Bantam rooster that I've had for 6 months, and I've only ever seen him mate 4 times, and had very few fertile eggs. I have set a few in the incubator and they all come out clear. He is currently in with only 1 hen, which is an EE. At one time, we also had 3 Barred Rocks, and he did mate with them, but I only saw a few times. The fertility of their eggs were hit an miss. Although he is a Bantam, and the hens are a standard size, from what I've seen, the mating process looks successful. Has anyone else had this problem? I'm wanting to get some good hatching eggs, so should I replace this rooster? I know it's not a good idea for only 1 rooster to 1 hen, but I figured he's not mating her anyway. Maybe I should put some more hens with him again and see what happens, since he seemed to like the Barred Rocks much better. Also, could there be something wrong with him?