Pig Aggression

Question
I have had two brothers for about a year now.  They have mostly gotten along well, with only occasional flare ups of fighting or chasing.  The past few weeks Muffin, the slightly bigger one, has been chasing his brother Quincy ruthlessly.  It is a large cage, with two levels, but he won't leave him alone.  Fur has been flying.  We use an evening run around time to give them fresh veggies and grass outside their cage (they only mess on the newspaper or in the cage).  The past weeks, muffin has been chasing quincy away from the food.  For the first year this was no problem.  I can't pinpoint any change in environment or handling.  Is there something about 15 month old pigs that can make them suddenly more aggresive?  Do you have any tips for me to help Quincy out?  He is about 150 grams lighter than his 1.2 kilo brother and is seeming a bit oppressed.
Thanks

Carl Moyer

Answer
Hello, the best thing to do and the only thing to do is to seperate both guinea pigs. Male guinea pigs generally don't like to stay with each other and prefer to be away from each other. Generally with males it's best to keep them seperated because they have a great tendancy to fight once they are older, If you don't seperate them you may just end up with one guinea pig.