Puberty in rats

I recently became interrested in onset of puberty in rats. I found this priceless piece of research, who thinks about stuff like this: "Ventral, dorsal, and lateral prostates and seminal vesicles were significantly lighter in those rats wearing collars that prevented self-grooming. It was concluded that self-grooming, probably of the genitals, contributes to accessory organ growth in males of this species." So licking genitals makes them grow eh...