I've been dealing with LMB for a long time and I wouldn't even trust myself 100% of the time on making an accurate sexing decision. Even catching males off the nest, you just don't know for sure it wasn't a female there at the wrong time. I love the idea of doing female only LMB. I'd love to put a handful in my future SMB pond, but I just don't want to take the risk. It just takes 1 male and it's all over! In the spring during the spawn, you may be able to squeeze bass and see if they release milt or eggs, but you just can't be sure. I would love to do the same thing for crappies as well. Adult BG have very distinct sexual dimorphism making it easy to sex them. YP are fairly easily sex through the squeezing method... One member on here has a smaller pond and only put in what I remember to be 4 what he thought were single sex LMB, but oops they weren't...