There are a few ways you can do it. When they are very young you can do what's called popping which involves everting the hemipenis of the male. Unfortunately, if you don't do it correctly sometimes you'll think that the male is a female, or you might mistake everted scent glands in the female for the hemipenis. It's not too difficult to learn, but it's best if someone shows you how. There is also candling. You can use a bright light source to sex some of the albino types such as blizzards, amels and snows this way. Lighting the rear can show up the hemipenis in males. I can however, tell you from experience that this can often be wrong too. My amel turned out to be all man....even though we thought he was a she due to candling. The most accurate way is to probe. You can purchase sexing probes from Kathy Love and various other places online. This also is best learned from someone who's done it before. Reading directions and actually doing it can be two different things. I'm just starting to get the hang of probing after having my friend Stephen show me how several times.