I know this is not 100 percent, but my question is, if you have a brood of small 1-2 inch red devils and one or two seem to be the largest of the bunch and are bulllying everyone else around, is it a good indication that these could be a males? i know its not 100 percent, i just purchased two and thats how i made my assumption, its not exact but could i be on the right track with this? thanks,R-