Happy guinea pigs are wonderfully expressive, and one of the most delightful signs is 'popcorning' โ a sudden joyful hop or twist, often seen during playtime or feeding time. Wheeking, a loud, excited squeal, is a classic sign of anticipation, especially when guinea pigs hear the fridge open or a bag rustle.
Soft purring or chattering-adjacent sounds during petting usually signal contentment, distinct from the sharper teeth-chattering that signals irritation. Relaxed, stretched-out lounging (rather than a tightly curled ball) shows a guinea pig feels safe in their space.
Guinea pigs are also social animals, so a happy guinea pig kept with a bonded companion will often groom, cuddle, or simply sit close to their cage mate. If your guinea pig approaches the front of the cage at your presence rather than hiding, that's a good sign they feel comfortable with you too.