Is there a dirt patch under each plant... any nutrient residue or any marks of chemicals or nutrients being used? Because that could be a sign that they are someones... You could go to your local flower store and buy a NPK Test kit to see if it has high levels. Also if the plant has been topped or Fimmed could mean that they were someones.

Pull all of the males and start feeding it some nutrients. Make sure your light on your dosage if you do because if someone else is giving giving them some already then it could burn it.