Hi! i have 2 male guinea pigs, i bought them both from pet shops. the first one i got on the 21st of January 2012 and the other on April 1st 2012. they are full grown now im pretty sure and i think they hit maturity and they are fighting! im not sure if its fighting or showing dominance! the one that i got in April is a short hair and is a tiny bit smaller then the other one that is an Abyssinian! the little bosses the bigger one around a but and today i had him out and i seen a cut/ scrape on the bald spot behind his ear, im not sure if its a fly bite he might have scratched? because there was a fly in my room all last night and i could not find it and kill it. Should i separate the two? I dont think there was any blood on the scratch. and i dont think it hurts him. here are some pictures of it. oh and by the way, they have a 2x4 C+C cage