I've got two very cute Guinea pigs called Pepper and Ziggy. They appear very similar in features, except for their colour, and were together when I bought them (as there were none in any local shelters) so I have reason to believe they may be sisters, or at least somehow related.
They've never exactly shown sisterly behavior though.
It's always been fairly harmless, but I'd never seen this before and I'm wondering if it's normal behavior..
Pepper was chewing on some grass, as was Ziggy when she started eating a little closer to Pepper, and they were now facing each other. Pepper raised her head, very slowly, then turned around quickly and sprayed urine back at the spot were Ziggy was. Luckily, Ziggy got away in time, as she had obviously experienced it before.
Is this normal?
They've always been pretty territorial about who gets which part of the hutch, so all I can put it down to is some sort of 'marking' or perhaps it was just aggression..