Not conclusively, unless you pop them in an attempt to evert the hemipenes when they are young. If you do this without really knowing what you are doing you can damage ther tails and sex organs as well. More so if you do it when they are too old for that method to be safe. People say you can look at tail length but that's an educated guess at best. Was at a store yesterday and heard an iemployee confidently state you can tell by the curvature of the spurs - he used this method to sell them a female to match the male he had sold them weeks earlier. Utter crapshoot there. Best bet is to go to a vet, herp show or if you are confident in the staff SOME (be damn careful here) pet stores can do it. I'd be really hard pressed to trust them though. Indidently this guy who was misguidedly sexing by spurs admitted to the folks he was "setting up with a breedable pair" had NO CLUE whether BP's gave birth live (vivaparous) or via eggs (oviparous). Gad-fecking-zooks I say!!