two male rats mating??!!

Question
i have two male rats not from the same litter but the same age and have been together since they were babies.. one is a large blue dumbo and the other is a fairly small double rex (virtually hairless)...
PROBLEM: it seem that the bald rat (RABBIT) keeps trying to mount/mate with Cornelius (the blue rat)... i mean i have nothing against homosexuality but after a while cornius gets mad at rabbit and bites him... being that he has no coat for potection he normally ends up with a large chunk of skin removed!! obviousy i treat it and it always heals fine but he then goes back for more!! and the whole cycle continues... i really don't want to seperate them and castrating them is too risky, will he grow out of it?? (the injuries probably happen about every 1-2 weeks and don't seem to bother him) i just don't want it to get really out of hand 'cause some real damage might be done!
thanks for any help given..
Zoe Pocock, lONDON, UK

Answer
Hi Zoe

Rats are not homosexual. What your witnessing is typical male dominance.

It seems that Rabbit is letting Cornelius know who is boss and it really doesn't have anything to do with being sexually aroused in the least bit.

I am going  to assume they are between 6 and 7 months old? You didn't mention their age other than they are the same age.
Puberty begins for them around this age and ends around the age of 1 years old. During this time, testosterone levels rise and the more dominating male wants to assume his position as alpha male.

True aggression can be corrected through neutering and although there is always a risk with anesthesia, if the surgeon is skilled with surgery on rats, the risks are minimal. Neutering is done all the time on male rats with hardly any incidence of complications in a normal healthy male.

However, I do feel what is happening is pretty normal dominance that he will grow out of. Try to stimulate them more by having them use up their energy perhaps extending play time out of the cage or taking them out more often to play.

Meanwhile, when the other rat does get hurt you can apply a topical antibiotic ointment on the area as long as its not too deep and bleeding  but infection is a possible complication which is why I would consider neutering the aggressor if it gets any more serious.
At that point, it isn't worth risking the safety of Cornelius while waiting for Rabbit to outgrow it just in case this is true aggression that neutering can easily correct.

Do you have a vet that is skilled in rat care?

Hope this helps and I do hope things go a bit better for the boys and for you!