i agree with jason,there pretty hard to sex,i had a big solid one,boofy head and thick tail base and aggressive to the other cunnighams i had at the time actually have babys on me,i would have sworn male,as males are usually quite aggressive,but yeah,there are exceptions,behaviour is pretty reliable though,if u have 2 males of size,or at least of breeding age they will generally fight,they get quite aggressive,other wise,go by the never had bubs,probably male,dropped bubs omg its a female