interesting! It turns out the problem is the testes can retract up to 16 inches into the body and it's a difficult procedure. In fact it says its hard to tell genders apart because of the way their penis retracts so far.

But the study of castrating 10 males work almost perfectly and they showed less aggression... in fact the females were more likely to bully and harass castrated males. So not all is lost but they are still a challenge.