i have 4 neutered male rats, two were neutered later, and 2 were neutered young, my younger boys have never marked me, and behave more like submissivee licky girls, anouter rat i got neutered when he was one year, he still marks but not nearly as much, he used to run to your sock and pee, he dosn't do that anymore. the other one was a bit older, but i am not sure how old because he is a reasue, i woulf think he was at least 15 months when neutered. i didn't get him too long before that so i don't know how he was before. he never marks me. just likes to chew my hair...