As far as I know, no you cant probe. I believe the only sure fire methods is if one falls pregnant, gets another pregnant, a male drops sperm plugs (but not all do/ are noticeable) and if your lucky you might see a males hemepenes before he brings them back in. The last two methods only determines if its male though, as obviously females dont do it, yet some males are never caught. So yeah, quite a difficult process
Unless you plan on breeding, you could just do what I do and call everything a 'he'
