2 chi brother question..

Question
I have 2 chi's, brothers from same litter.  They are 3.5 months old. One smaller (dominate one) then other. Just recently (as in today) they have been "aggressively" humping each other. I've had male dogs before and never saw this "aggressive" behavior.  I've seperated them, but being litter mates, they hate to be apart from each other. I Plan on having them neutered in very near future.  Will this stop this sort of behavior and is it a normal "coming of age" issue?  And the other question is.. I was told by the breeder I got the pups from that maybe they can smell a female in heat in my neighborhood and just taking their sexual frustration out on each other.  At 3.5 months, is that too young for that or is it simular to puberty?

Answer
Hi Wendy-

around 4 months is when males begin noticing bitches in heat- they may not understand whats going on, but they CAN smell them... and from up to three miles away!

Most likely it is hormones coming to play, and your males are trying to determine who is dominate. Humping is not always sexual behavior, but is in fact USUALLY dominance play. The humper of course saying he is most dominate. Neutering will certainly slow, if not stop entirelly, this behavior, because you will be removing the hormones in question, however some neutered dogs and in fact many bitches and spayed bitches "hump" all their lives, to show who is boss.