Alicia
Adult Guinea Pig
Amber is now 4 months old and she's so tame that I can just pick her up and she won't move (may partly be because I think she's blind) While I refill the water bottles for the hutches I bring her in with me and let her walk round the kitchen in a closed of area, and today I gave her a handful of grass to have while I refilled the water bottles. After she'd eaten her grass she went and hid behind the bin and so I picked her up and put her on my lap. I was stroking her hair from the back to the front just checking her coat and she started kind of purring and then settled into my lap. I know boars can do this with sows but Amber is definetly a sow. Does this mean she's happy?
But sometimes, they make a similar sound, and it resembles fear. But in your case, I think she is happy.