I separate the cleaned headless fish into groups of 2-3, wrap them in plastic wrap and refreeze the groups. About once a week I defrost a clump, cut them in half and boil them for about 8 minutes, allowing them to reach room temperature before I remove the bones and fin spines and give it to them in the stainless steel food dishes I use. I have utilized these shallow bowls for over fifteen years and they are literally unbreakable and easy to clean. I keep the dry food bowl always full. They do appreciate some milk also.
Males seem to take a bit longer to reach sexual maturity.
I theorize that the basic underlying chemical structure of these sexually stimulating, response activating aromas must be similar in both cats and humans. OK, so now we have to wait 9 weeks for the new kittys to arrive. I was familiar with their normal sounds and theorized that a pregnant dam would have a totally different voice when she was in labor. One night, while I was asleep with all of them under the covers with me, the pregnant one woke me with loud deep moans. I immediately put her in a box with layers of towels on the bottom, and that is where she had her first litter.