Palpation is very accurate with young boas - no need to probe or pop. Sounds like you know how and what to feel for, but just in case - and for others sakes, run your thumb down the underside of the tail starting at the vent. Use firm pressure (not enough to turn the tip of your thumb white, lol, but enough to really feel). As you travel down the tail, you will feel a slight pop as though you've run over a small speed bump. These are the hemipenes. If you do not feel that, it's a girl. Again, this is very accurate. But you do need to make sure you're feeling down far enough - the hemipenes are often almost 1/2 way from the vent to the tail tip or more.![]()